src/CPU.h


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57

#pragma once

#include <cstdint>
#include <memory>

#include "Instruction.h"
#include "Bus.h"
#include "ExecutorCases.h"
#include "CPUContext.h"

enum class CPUExecutionMode {
  BIT_32,
};

struct CPUStatus {
    uint32_t* m_Registers;
    uint32_t& m_IP;
    Instruction& m_Instruction;
};

class CPU {
public:
  CPU(std::shared_ptr<Bus>& bus);
  ~CPU() = default;

public:
  void Step();

  void Dump();
  void Reset();
  
  bool IsHalted() { return m_IsHalted; }

  CPUStatus GetStatus();
  
private:
  void FetchDecode();
  void Execute();

private:
  CPUExecutionMode m_Mode;
  uint32_t m_Registers[8];
  uint16_t m_SegmentRegisters[8];
  uint32_t m_InstructionPointer;
  uint32_t m_Flags;
  bool m_IsHalted;
  
  std::shared_ptr<Bus> m_Bus;

  Instruction m_Instruction;
  
  CPUContext m_Context;
private:
  // FetchDecode() must set m_Length before calling FetchModRMFields()
  void FetchModRMFields(uint8_t modrm);
  void FetchSIB();
};