/* xgate-dis.c -- Freescale XGATE disassembly
Copyright (C) 2009-2020 Free Software Foundation, Inc.
Written by Sean Keys (skeys@ipdatasys.com)
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 program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include <assert.h>
#include "disassemble.h"
#include "opintl.h"
#include "libiberty.h"
#include "ansidecl.h"
#include "opcode/xgate.h"
#define XGATE_TWO_BYTES 0x02
#define XGATE_NINE_BITS 0x1FF
#define XGATE_TEN_BITS 0x3FF
#define XGATE_NINE_SIGNBIT 0x100
#define XGATE_TEN_SIGNBIT 0x200
/* Structures. */
struct decodeInfo
{
unsigned int operMask;
unsigned int operMasksRegisterBits;
struct xgate_opcode *opcodePTR;
};
/* Prototypes for local functions. */
static int print_insn (bfd_vma, struct disassemble_info *);
static int read_memory (bfd_vma, bfd_byte*, int, struct disassemble_info *);
static int ripBits (unsigned int *, int,
struct xgate_opcode *, unsigned int);
static int macro_search (char *, char *);
static struct decodeInfo * find_match (unsigned int);
/* Statics. */
static struct decodeInfo *decodeTable;
static int initialized;
static char previousOpName[10];
static unsigned int perviousBin;
/* Disassemble one instruction at address 'memaddr'. Returns the number
of bytes used by that instruction. */
static int
print_insn (bfd_vma memaddr, struct disassemble_info* info)
{
int status;
unsigned int raw_code;
char *s = 0;
long bytesRead = 0;
int i = 0;
struct xgate_opcode *opcodePTR = (struct xgate_opcode*) xgate_opcodes;
struct decodeInfo *decodeTablePTR = 0;
struct decodeInfo *decodePTR = 0;
unsigned int operandRegisterBits = 0;
signed int relAddr = 0;
signed int operandOne = 0;
signed int operandTwo = 0;
bfd_byte buffer[4];
bfd_vma absAddress;
unsigned int operMaskReg = 0;
/* Initialize our array of opcode masks and check them against our constant
table. */
if (!initialized)
{
decodeTable = xmalloc (sizeof (struct decodeInfo) * xgate_num_opcodes);
for (i = 0, decodeTablePTR = decodeTable; i < xgate_num_opcodes;
i++, decodeTablePTR++, opcodePTR++)
{
unsigned int bin = 0;
unsigned int mask = 0;
for (s = opcodePTR->format; *s; s++)
{
bin <<= 1;
mask <<= 1;
operandRegisterBits <<= 1;
bin |= (*s == '1');
mask |= (*s == '0' || *s == '1');
operandRegisterBits |= (*s == 'r');
}
/* Asserting will uncover inconsistencies in our table. */
assert ((s - opcodePTR->format) == 16 || (s - opcodePTR->format) == 32);
assert (opcodePTR->bin_opcode == bin);
decodeTablePTR->operMask = mask;
decodeTablePTR->operMasksRegisterBits = operandRegisterBits;
decodeTablePTR->opcodePTR = opcodePTR;
}
initialized = 1;
}
/* Read 16 bits. */
bytesRead += XGATE_TWO_BYTES;
status = read_memory (memaddr, buffer, XGATE_TWO_BYTES, info);
if (status == 0)
{
raw_code = buffer[0];
raw_code <<= 8;
raw_code += buffer[1];
decodePTR = find_match (raw_code);
if (decodePTR)
{
operMaskReg = decodePTR->operMasksRegisterBits;
(*info->fprintf_func)(info->stream, "%s", decodePTR->opcodePTR->name);
/* First we compare the shorthand format of the constraints. If we
still are unable to pinpoint the operands
we analyze the opcodes constraint string. */
if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_R_C))
{
(*info->fprintf_func)(info->stream, " R%x, CCR",
(raw_code >> 8) & 0x7);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_C_R))
{
(*info->fprintf_func)(info->stream, " CCR, R%x",
(raw_code >> 8) & 0x7);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_R_P))
{
(*info->fprintf_func)(info->stream, " R%x, PC",
(raw_code >> 8) & 0x7);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_TRI))
{
(*info->fprintf_func)(info->stream, " R%x, R%x, R%x",
(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
(raw_code >> 2) & 0x7);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IDR))
{
if (raw_code & 0x01)
{
(*info->fprintf_func)(info->stream, " R%x, (R%x, R%x+)",
(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
(raw_code >> 2) & 0x7);
}
else if (raw_code & 0x02)
{
(*info->fprintf_func)(info->stream, " R%x, (R%x, -R%x)",
(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
(raw_code >> 2) & 0x7);
}
else
{
(*info->fprintf_func)(info->stream, " R%x, (R%x, R%x)",
(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
(raw_code >> 2) & 0x7);
}
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_DYA))
{
operandOne = ripBits (&operMaskReg, 3, decodePTR->opcodePTR, raw_code);
operandTwo = ripBits (&operMaskReg, 3, decodePTR->opcodePTR, raw_code);
( *info->fprintf_func)(info->stream, " R%x, R%x", operandOne,
operandTwo);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IDO5))
{
(*info->fprintf_func)(info->stream, " R%x, (R%x, #0x%x)",
(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7, raw_code & 0x1f);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON))
{
operandOne = ripBits (&operMaskReg, 3, decodePTR->opcodePTR,
raw_code);
(*info->fprintf_func)(info->stream, " R%x", operandOne);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_REL9))
{
/* If address is negative handle it accordingly. */
if (raw_code & XGATE_NINE_SIGNBIT)
{
relAddr = XGATE_NINE_BITS >> 1; /* Clip sign bit. */
relAddr = ~relAddr; /* Make signed. */
relAddr |= (raw_code & 0xFF) + 1; /* Apply our value. */
relAddr *= 2; /* Multiply by two as per processor docs. */
}
else
{
relAddr = raw_code & 0xff;
relAddr = relAddr * 2 + 2;
}
(*info->fprintf_func)(info->stream, " *%d", relAddr);
(*info->fprintf_func)(info->stream, " Abs* 0x");
(*info->print_address_func)(memaddr + relAddr, info);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_REL10))
{
/* If address is negative handle it accordingly. */
if (raw_code & XGATE_TEN_SIGNBIT)
{
relAddr = XGATE_TEN_BITS >> 1; /* Clip sign bit. */
relAddr = ~relAddr; /* Make signed. */
relAddr |= (raw_code & 0x1FF) + 1; /* Apply our value. */
relAddr *= 2; /* Multiply by two as per processor docs. */
}
else
{
relAddr = raw_code & 0x1FF;
relAddr = relAddr * 2 + 2;
}
(*info->fprintf_func)(info->stream, " *%d", relAddr);
(*info->fprintf_func)(info->stream, " Abs* 0x");
(*info->print_address_func)(memaddr + relAddr, info);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM4))
{
(*info->fprintf_func)(info->stream, " R%x, #0x%02x",
(raw_code >> 8) & 0x7, (raw_code >> 4) & 0xF);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM8))
{
if (macro_search (decodePTR->opcodePTR->name, previousOpName) &&
previousOpName[0])
{
absAddress = (0xFF & raw_code) << 8;
absAddress |= perviousBin & 0xFF;
(*info->fprintf_func)(info->stream, " R%x, #0x%02x Abs* 0x",
(raw_code >> 8) & 0x7, raw_code & 0xff);
(*info->print_address_func)(absAddress, info);
previousOpName[0] = 0;
}
else
{
strcpy (previousOpName, decodePTR->opcodePTR->name);
(*info->fprintf_func)(info->stream, " R%x, #0x%02x",
(raw_code >> 8) & 0x7, raw_code & 0xff);
}
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM3))
{
(*info->fprintf_func)(info->stream, " #0x%x",
(raw_code >> 8) & 0x7);
}
else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_INH))
{
//
}
else
{
(*info->fprintf_func)(info->stream, " unhandled mode %s",
decodePTR->opcodePTR->constraints);
}
perviousBin = raw_code;
}
else
{
(*info->fprintf_func)(info->stream,
" unable to find opcode match #0%x", raw_code);
}
}
return bytesRead;
}
int
print_insn_xgate (bfd_vma memaddr, struct disassemble_info* info)
{
return print_insn (memaddr, info);
}
static int
read_memory (bfd_vma memaddr, bfd_byte* buffer, int size,
struct disassemble_info* info)
{
int status;
status = (*info->read_memory_func) (memaddr, buffer, size, info);
if (status != 0)
{
(*info->memory_error_func) (status, memaddr, info);
return -1;
}
return 0;
}
static int
ripBits (unsigned int *operandBitsRemaining,
int numBitsRequested,
struct xgate_opcode *opcodePTR,
unsigned int memory)
{
unsigned int currentBit;
unsigned int operand = 0;
int numBitsFound;
for (numBitsFound = 0, currentBit = 1u << ((opcodePTR->size * 8) - 1);
numBitsFound < numBitsRequested && currentBit != 0;
currentBit >>= 1)
{
if (currentBit & *operandBitsRemaining)
{
*operandBitsRemaining &= ~(currentBit); /* Consume the current bit. */
operand <<= 1; /* Make room for our next bit. */
numBitsFound++;
operand |= (currentBit & memory) > 0;
}
}
return operand;
}
static int
macro_search (char *currentName, char *lastName)
{
int i;
int length = 0;
char *where;
for (i = 0; i < xgate_num_opcodes; i++)
{
where = strstr (xgate_opcodes[i].constraints, lastName);
if (where)
{
length = strlen (where);
}
if (length)
{
where = strstr (xgate_opcodes[i].constraints, currentName);
if (where)
{
length = strlen (where);
return 1;
}
}
}
return 0;
}
static struct decodeInfo *
find_match (unsigned int raw_code)
{
struct decodeInfo *decodeTablePTR = 0;
int i;
for (i = 0, decodeTablePTR = decodeTable; i < xgate_num_opcodes;
i++, decodeTablePTR++)
{
if ((raw_code & decodeTablePTR->operMask)
== decodeTablePTR->opcodePTR->bin_opcode)
{
/* Make sure we didn't run into a macro or alias. */
if (decodeTablePTR->opcodePTR->cycles_min != 0)
{
return decodeTablePTR;
break;
}
else
continue;
}
}
return 0;
}