vgbc/cpu/cpu.h

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#pragma once
#include "types.h"
#include "memory/mem_device.h"
typedef u8 opcode_t;
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enum Flags {
F_ZERO = 0x8,
F_SUB = 0x4,
F_HALF = 0x2,
F_CARRY = 0x1,
};
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enum AluOp : int {
ADD = 0,
ADC = 1,
SUB = 2,
SBC = 3,
AND = 4,
XOR = 5,
OR = 6,
CP = 7,
};
enum CC
{
COND_NZ = 0,
COND_Z = 1,
COND_NC = 2,
COND_C = 3,
};
enum InterruptType : u8
{
INT_VBlank = 0x1,
INT_LCDSTAT = 0x2,
INT_Timer = 0x4,
INT_Serial = 0x8,
INT_Joypad = 0x10,
INT_MASK = 0x1F,
};
enum IME_state
{
IME_OFF,
IME_SCHEDULED,
IME_DELAYED,
IME_ON,
};
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struct Cpu_state {
// Registers
union {
u16 BC;
struct { u8 B; u8 C; };
};
union {
u16 DE;
struct { u8 D; u8 E; };
};
union {
u16 HL;
struct { u8 H; u8 L; };
};
u8 A;
u16 SP;
u16 PC;
bool zero;
bool subtract;
bool halfcarry;
bool carry;
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IME_state IME;
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u8 IE;
u8 IF;
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void setAF(u16 v);
u16 getAF();
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};
class Cpu {
private:
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u8 readPC8();
u16 readPC16();
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void pushStack8(u8 data);
u8 popStack8();
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void pushStack16(u16 data);
u16 popStack16();
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void aluop8(AluOp op, u8 lhs, u8 rhs, u8& out, bool update_carry = true);
inline
void aluop8(AluOp op, u8 rhs, bool update_carry = true)
{
aluop8(op, state.A, rhs, state.A, update_carry);
}
void doCall(u16 target);
void doRet();
bool decodeCond(u8 cc);
void handleInterrupts();
void executeInstruction();
void reset();
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public:
Cpu(Mem_device* bus);
Cpu_state state;
Mem_device* bus;
unsigned long processed_mcycles;
void signal(InterruptType it);
void setIE(u8 val);
u8 getIE();
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void step();
};