/* OpenIDA - Outil d'analyse de fichiers binaires
 * op_dec.c - décodage des décrémentations
 *
 * Copyright (C) 2008 Cyrille Bagard
 *
 *  This file is part of OpenIDA.
 *
 *  OpenIDA 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.
 *
 *  OpenIDA 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 Foobar.  If not, see <http://www.gnu.org/licenses/>.
 */


#include <malloc.h>


#include "../instruction-int.h"
#include "opcodes.h"
#include "operand.h"



/******************************************************************************
*                                                                             *
*  Paramètres  : data   = flux de données à analyser.                         *
*                pos    = position courante dans ce flux. [OUT]               *
*                len    = taille totale des données à analyser.               *
*                offset = adresse virtuelle de l'instruction.                 *
*                proc   = architecture ciblée par le désassemblage.           *
*                                                                             *
*  Description : Décode une instruction de type 'inc' (16 ou 32 bits).        *
*                                                                             *
*  Retour      : Instruction mise en place ou NULL.                           *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

asm_x86_instr *read_instr_dec_1632(const uint8_t *data, off_t *pos, off_t len, uint64_t offset, const asm_x86_processor *proc)
{
    asm_x86_instr *result;                  /* Instruction à retourner     */
    AsmOperandSize oprsize;                 /* Taille des opérandes        */
    asm_x86_operand *reg;                   /* Registre de destination     */

    result = (asm_x86_instr *)calloc(1, sizeof(asm_x86_instr));

    /* Utilisation des registres 32 bits ? */
    if (data[*pos] == 0x66)
    {
        oprsize = switch_x86_operand_size(proc);
        (*pos)++;
    }
    else oprsize = get_x86_current_operand_size(proc);

    ASM_INSTRUCTION(result)->opcode = data[*pos];

    reg = x86_create_reg1632_operand(data[(*pos)++], oprsize == AOS_32_BITS, 0x48);
    if (reg == NULL)
    {
        free(result);
        return NULL;
    }

    ASM_INSTRUCTION(result)->operands = (asm_operand **)calloc(1, sizeof(asm_operand *));
    ASM_INSTRUCTION(result)->operands_count = 1;

    ASM_INSTRUCTION(result)->operands[0] = ASM_OPERAND(reg);

    return result;

}