mirror of
https://github.com/autc04/Retro68.git
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372 lines
12 KiB
C
372 lines
12 KiB
C
/* xgate-dis.c -- Freescale XGATE disassembly
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Copyright (C) 2009-2018 Free Software Foundation, Inc.
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Written by Sean Keys (skeys@ipdatasys.com)
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This file is part of the GNU opcodes library.
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This library is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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It is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include "sysdep.h"
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#include <assert.h>
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#include "disassemble.h"
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#include "opintl.h"
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#include "libiberty.h"
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#include "ansidecl.h"
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#include "opcode/xgate.h"
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#define XGATE_TWO_BYTES 0x02
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#define XGATE_NINE_BITS 0x1FF
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#define XGATE_TEN_BITS 0x3FF
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#define XGATE_NINE_SIGNBIT 0x100
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#define XGATE_TEN_SIGNBIT 0x200
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/* Structures. */
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struct decodeInfo
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{
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unsigned int operMask;
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unsigned int operMasksRegisterBits;
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struct xgate_opcode *opcodePTR;
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};
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/* Prototypes for local functions. */
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static int print_insn (bfd_vma, struct disassemble_info *);
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static int read_memory (bfd_vma, bfd_byte*, int, struct disassemble_info *);
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static int ripBits (unsigned int *, int,
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struct xgate_opcode *, unsigned int);
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static int macro_search (char *, char *);
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static struct decodeInfo * find_match (unsigned int);
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/* Statics. */
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static struct decodeInfo *decodeTable;
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static int initialized;
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static char previousOpName[10];
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static unsigned int perviousBin;
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/* Disassemble one instruction at address 'memaddr'. Returns the number
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of bytes used by that instruction. */
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static int
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print_insn (bfd_vma memaddr, struct disassemble_info* info)
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{
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int status;
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unsigned int raw_code;
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char *s = 0;
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long bytesRead = 0;
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int i = 0;
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struct xgate_opcode *opcodePTR = (struct xgate_opcode*) xgate_opcodes;
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struct decodeInfo *decodeTablePTR = 0;
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struct decodeInfo *decodePTR = 0;
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unsigned int operandRegisterBits = 0;
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signed int relAddr = 0;
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signed int operandOne = 0;
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signed int operandTwo = 0;
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bfd_byte buffer[4];
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bfd_vma absAddress;
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unsigned int operMaskReg = 0;
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/* Initialize our array of opcode masks and check them against our constant
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table. */
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if (!initialized)
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{
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decodeTable = xmalloc (sizeof (struct decodeInfo) * xgate_num_opcodes);
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for (i = 0, decodeTablePTR = decodeTable; i < xgate_num_opcodes;
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i++, decodeTablePTR++, opcodePTR++)
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{
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unsigned int bin = 0;
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unsigned int mask = 0;
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for (s = opcodePTR->format; *s; s++)
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{
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bin <<= 1;
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mask <<= 1;
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operandRegisterBits <<= 1;
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bin |= (*s == '1');
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mask |= (*s == '0' || *s == '1');
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operandRegisterBits |= (*s == 'r');
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}
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/* Asserting will uncover inconsistencies in our table. */
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assert ((s - opcodePTR->format) == 16 || (s - opcodePTR->format) == 32);
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assert (opcodePTR->bin_opcode == bin);
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decodeTablePTR->operMask = mask;
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decodeTablePTR->operMasksRegisterBits = operandRegisterBits;
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decodeTablePTR->opcodePTR = opcodePTR;
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}
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initialized = 1;
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}
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/* Read 16 bits. */
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bytesRead += XGATE_TWO_BYTES;
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status = read_memory (memaddr, buffer, XGATE_TWO_BYTES, info);
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if (status == 0)
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{
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raw_code = buffer[0];
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raw_code <<= 8;
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raw_code += buffer[1];
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decodePTR = find_match (raw_code);
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if (decodePTR)
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{
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operMaskReg = decodePTR->operMasksRegisterBits;
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(*info->fprintf_func)(info->stream, "%s", decodePTR->opcodePTR->name);
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/* First we compare the shorthand format of the constraints. If we
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still are unable to pinpoint the operands
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we analyze the opcodes constraint string. */
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if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_R_C))
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{
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(*info->fprintf_func)(info->stream, " R%x, CCR",
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(raw_code >> 8) & 0x7);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_C_R))
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{
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(*info->fprintf_func)(info->stream, " CCR, R%x",
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(raw_code >> 8) & 0x7);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_R_P))
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{
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(*info->fprintf_func)(info->stream, " R%x, PC",
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(raw_code >> 8) & 0x7);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_TRI))
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{
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(*info->fprintf_func)(info->stream, " R%x, R%x, R%x",
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(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
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(raw_code >> 2) & 0x7);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IDR))
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{
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if (raw_code & 0x01)
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{
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(*info->fprintf_func)(info->stream, " R%x, (R%x, R%x+)",
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(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
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(raw_code >> 2) & 0x7);
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}
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else if (raw_code & 0x02)
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{
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(*info->fprintf_func)(info->stream, " R%x, (R%x, -R%x)",
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(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
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(raw_code >> 2) & 0x7);
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}
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else
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{
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(*info->fprintf_func)(info->stream, " R%x, (R%x, R%x)",
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(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
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(raw_code >> 2) & 0x7);
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}
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_DYA))
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{
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operandOne = ripBits (&operMaskReg, 3, opcodePTR, raw_code);
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operandTwo = ripBits (&operMaskReg, 3, opcodePTR, raw_code);
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( *info->fprintf_func)(info->stream, " R%x, R%x", operandOne,
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operandTwo);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IDO5))
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{
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(*info->fprintf_func)(info->stream, " R%x, (R%x, #0x%x)",
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(raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7, raw_code & 0x1f);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON))
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{
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operandOne = ripBits (&operMaskReg, 3, decodePTR->opcodePTR,
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raw_code);
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(*info->fprintf_func)(info->stream, " R%x", operandOne);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_REL9))
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{
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/* If address is negative handle it accordingly. */
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if (raw_code & XGATE_NINE_SIGNBIT)
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{
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relAddr = XGATE_NINE_BITS >> 1; /* Clip sign bit. */
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relAddr = ~relAddr; /* Make signed. */
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relAddr |= (raw_code & 0xFF) + 1; /* Apply our value. */
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relAddr <<= 1; /* Multiply by two as per processor docs. */
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}
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else
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{
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relAddr = raw_code & 0xff;
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relAddr = (relAddr << 1) + 2;
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}
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(*info->fprintf_func)(info->stream, " *%d", relAddr);
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(*info->fprintf_func)(info->stream, " Abs* 0x");
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(*info->print_address_func)(memaddr + relAddr, info);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_REL10))
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{
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/* If address is negative handle it accordingly. */
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if (raw_code & XGATE_TEN_SIGNBIT)
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{
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relAddr = XGATE_TEN_BITS >> 1; /* Clip sign bit. */
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relAddr = ~relAddr; /* Make signed. */
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relAddr |= (raw_code & 0x1FF) + 1; /* Apply our value. */
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relAddr <<= 1; /* Multiply by two as per processor docs. */
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}
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else
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{
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relAddr = raw_code & 0x1FF;
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relAddr = (relAddr << 1) + 2;
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}
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(*info->fprintf_func)(info->stream, " *%d", relAddr);
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(*info->fprintf_func)(info->stream, " Abs* 0x");
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(*info->print_address_func)(memaddr + relAddr, info);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM4))
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{
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(*info->fprintf_func)(info->stream, " R%x, #0x%02x",
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(raw_code >> 8) & 0x7, (raw_code >> 4) & 0xF);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM8))
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{
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if (macro_search (decodePTR->opcodePTR->name, previousOpName) &&
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previousOpName[0])
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{
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absAddress = (0xFF & raw_code) << 8;
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absAddress |= perviousBin & 0xFF;
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(*info->fprintf_func)(info->stream, " R%x, #0x%02x Abs* 0x",
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(raw_code >> 8) & 0x7, raw_code & 0xff);
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(*info->print_address_func)(absAddress, info);
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previousOpName[0] = 0;
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}
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else
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{
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strcpy (previousOpName, decodePTR->opcodePTR->name);
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(*info->fprintf_func)(info->stream, " R%x, #0x%02x",
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(raw_code >> 8) & 0x7, raw_code & 0xff);
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}
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM3))
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{
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(*info->fprintf_func)(info->stream, " #0x%x",
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(raw_code >> 8) & 0x7);
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}
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else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_INH))
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{
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//
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}
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else
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{
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(*info->fprintf_func)(info->stream, " unhandled mode %s",
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opcodePTR->constraints);
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}
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perviousBin = raw_code;
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}
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else
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{
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(*info->fprintf_func)(info->stream,
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" unable to find opcode match #0%x", raw_code);
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}
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}
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return bytesRead;
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}
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int
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print_insn_xgate (bfd_vma memaddr, struct disassemble_info* info)
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{
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return print_insn (memaddr, info);
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}
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static int
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read_memory (bfd_vma memaddr, bfd_byte* buffer, int size,
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struct disassemble_info* info)
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{
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int status;
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status = (*info->read_memory_func) (memaddr, buffer, size, info);
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if (status != 0)
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{
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(*info->memory_error_func) (status, memaddr, info);
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return -1;
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}
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return 0;
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}
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static int
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ripBits (unsigned int *operandBitsRemaining,
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int numBitsRequested,
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struct xgate_opcode *opcodePTR,
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unsigned int memory)
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{
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unsigned int currentBit;
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int operand;
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int numBitsFound;
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for (operand = 0, numBitsFound = 0, currentBit = 1
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<< ((opcodePTR->size * 8) - 1);
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(numBitsFound < numBitsRequested) && currentBit; currentBit >>= 1)
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{
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if (currentBit & *operandBitsRemaining)
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{
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*operandBitsRemaining &= ~(currentBit); /* Consume the current bit. */
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operand <<= 1; /* Make room for our next bit. */
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numBitsFound++;
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operand |= (currentBit & memory) > 0;
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}
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}
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return operand;
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}
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static int
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macro_search (char *currentName, char *lastName)
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{
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int i;
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int length = 0;
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char *where;
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for (i = 0; i < xgate_num_opcodes; i++)
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{
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where = strstr (xgate_opcodes[i].constraints, lastName);
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if (where)
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{
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length = strlen (where);
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}
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if (length)
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{
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where = strstr (xgate_opcodes[i].constraints, currentName);
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if (where)
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{
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length = strlen (where);
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return 1;
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}
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}
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}
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return 0;
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}
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static struct decodeInfo *
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find_match (unsigned int raw_code)
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{
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struct decodeInfo *decodeTablePTR = 0;
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int i;
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for (i = 0, decodeTablePTR = decodeTable; i < xgate_num_opcodes;
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i++, decodeTablePTR++)
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{
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if ((raw_code & decodeTablePTR->operMask)
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== decodeTablePTR->opcodePTR->bin_opcode)
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{
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/* Make sure we didn't run into a macro or alias. */
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if (decodeTablePTR->opcodePTR->cycles_min != 0)
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{
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return decodeTablePTR;
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break;
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}
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else
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continue;
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}
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}
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return 0;
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}
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