Subversion Repositories s80186

// Copyright Jamie Iles, 2017

//

// This file is part of s80x86.

//

// s80x86 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.

//

// s80x86 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 s80x86.  If not, see <http://www.gnu.org/licenses/>.

#pragma once

#include <stdint.h>

#include <functional>

#include <functional>

#include "RegisterFile.h"

enum OperandType {

    OP_REG,

    OP_MEM,

};

enum OperandWidth { OP_WIDTH_8, OP_WIDTH_16 };

class ModRMDecoder

{

public:

    ModRMDecoder(std::function<uint8_t()> get_byte,

                 const RegisterFile *registers);

    void clear();

    void set_width(OperandWidth width);

    void decode();

    GPR reg() const;

    int raw_reg() const;

    GPR rm_reg() const;

    uint16_t effective_address();

    OperandType rm_type() const;

    bool uses_bp_as_base() const;

private:

    uint16_t calculate_effective_address();

    uint16_t mod00();

    uint16_t mod01();

    uint16_t mod10();

    std::function<uint8_t()> get_byte;

    const RegisterFile *registers;

    OperandWidth width;

    uint8_t modrm;

    uint16_t cached_address;

    bool addr_is_cached;

    bool is_decoded;

};