86 lines
2.7 KiB
C++
86 lines
2.7 KiB
C++
#include "ExecutorCases.h"
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#include "Instruction.h"
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#include "Bus.h"
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#include <bitset>
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#include <iostream>
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CPUContext::CPUContext(Instruction& i, uint32_t& ip, uint32_t& flags, uint32_t* reg, std::shared_ptr<Bus>& bus, bool& isHalted) : m_Instruction(i), m_InstructionPointer(ip), m_Flags(flags), m_Registers(reg), m_Bus(bus), m_IsHalted(isHalted) { }
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CPUContext::~CPUContext() = default;
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// NO SIB SUPPORT YET
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namespace executor_cases {
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void Nop(CPUContext& cc){
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std::cout << "No op" << std::endl;
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}
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void Hlt(CPUContext& cc){
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std::cout << "Program halted!" << std::endl;
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exit(0);
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}
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void Mov_r32_imm32(CPUContext& cc){
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cc.m_Registers[cc.m_Instruction.m_Operand1] = cc.m_Instruction.m_Operand2;
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}
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void Add_rm32_r32(CPUContext& cc){
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x86::ModRM modrm = cc.m_Instruction.optional.m_ModRM;
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switch(modrm.m_State) {
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case x86::ModRMState::R:
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{
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cc.m_Registers[modrm.m_Rm] += cc.m_Registers[modrm.m_Reg];
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break;
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}
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case x86::ModRMState::LR:
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{
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uint32_t dstPrevValue = cc.m_Bus->AccessX<uint32_t>(cc.m_Registers[modrm.m_Rm]);
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uint32_t currRegValue = cc.m_Registers[modrm.m_Reg];
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uint32_t result = dstPrevValue + currRegValue;
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cc.m_Bus->WriteX<uint32_t>(cc.m_Registers[modrm.m_Rm], result);
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break;
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}
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case x86::ModRMState::LR_DISP8:
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case x86::ModRMState::LR_DISP32:
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{
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uint32_t dstAddress = cc.m_Registers[modrm.m_Rm] + cc.m_Instruction.m_Operand1;
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uint32_t dstPrevValue = cc.m_Bus->AccessX<uint32_t>(dstAddress);
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uint32_t currRegValue = cc.m_Registers[modrm.m_Reg];
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uint32_t result = dstPrevValue + currRegValue;
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cc.m_Bus->WriteX<uint32_t>(dstAddress, result);
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break;
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}
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case x86::ModRMState::DISP32:
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{
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uint32_t dstAddress = cc.m_Instruction.m_Operand1;
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uint32_t dstPrevValue = cc.m_Bus->AccessX<uint32_t>(dstAddress);
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uint32_t currRegValue = cc.m_Registers[modrm.m_Reg];
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uint32_t result = dstPrevValue + currRegValue;
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cc.m_Bus->WriteX<uint32_t>(dstAddress, result);
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break;
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}
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default:
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{
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throw std::runtime_error("Invalid ModRM State encountered during Add_rm32_r32");
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}
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}
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}
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}
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constexpr std::array<ExecutorCase, 255> GenerateExecutorTable(){
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std::array<ExecutorCase, 255> table{};
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table[Opcode::NOP] = executor_cases::Nop;
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table[Opcode::HLT] = executor_cases::Hlt;
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table[Opcode::MOV_R_IMM32] = executor_cases::Mov_r32_imm32;
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table[Opcode::ADD_RM32_R32] = executor_cases::Add_rm32_r32;
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return table;
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}
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static constexpr std::array<ExecutorCase, 255> s_ExecutorTable = GenerateExecutorTable();
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const std::array<ExecutorCase, 255>& GetExecutorTable() {
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return s_ExecutorTable;
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}
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