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Fixing OAM DMA. Removing logging.

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This commit is contained in:
Selim Mustafaev 2025-09-11 16:46:54 +03:00
parent ac688964e9
commit fbf80723d6
14 changed files with 92 additions and 212 deletions
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5
CMakeLists.txt
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@ -26,7 +26,7 @@ add_executable(nes
src/Controller.cpp
src/Controller.h
examples/sdl/SdlKeyboardController.cpp
examples/sdl/SdlKeyboardController.h src/Dma.cpp src/Dma.h
examples/sdl/SdlKeyboardController.h
src/Oam.cpp
src/Oam.h
src/Mapper/Mapper1.cpp
@ -38,5 +38,4 @@ add_executable(nes
examples/sdl/SdlGamepadController.h)
find_package(SDL3 CONFIG REQUIRED)
find_package(fmt REQUIRED)
target_link_libraries(nes PRIVATE SDL3::SDL3 fmt::fmt)
target_link_libraries(nes PRIVATE SDL3::SDL3)

20
src/Bus.cpp
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@ -3,6 +3,8 @@
//
#include "Bus.h"
#include "Cpu.h"
#include "Ppu.h"
#include <iostream>
namespace nes {
@ -12,18 +14,16 @@ namespace nes {
Ppu *ppu,
Cartridge *cartridge,
Controller *controller1,
Controller *controller2,
Dma *dma): _ram(ram),
_cpu(cpu),
_ppu(ppu),
_cartridge(cartridge),
_controller1(controller1),
_controller2(controller2),
_dma(dma) {
Controller *controller2):
_ram(ram),
_cpu(cpu),
_ppu(ppu),
_cartridge(cartridge),
_controller1(controller1),
_controller2(controller2) {
_cpu->connectToBus(this);
_ppu->connectToBus(this);
_dma->connectToBus(this);
}
void Bus::connectCartridge(Cartridge *cartridge) {
@ -83,7 +83,7 @@ namespace nes {
_ppu->write(address & 0x0007, value);
}
else if(address == 0x4014) {
_dma->start(value);
_ppu->startDma(value);
}
else if(address == 0x4016) {
_controller1->poll();

10
src/Bus.h
View File

@ -5,15 +5,15 @@
#ifndef BUS_H
#define BUS_H
#include "Cpu.h"
#include "Ppu.h"
#include "Cartridge.h"
#include "Controller.h"
#include "Dma.h"
#include <cstdint>
namespace nes {
class Cpu;
class Ppu;
class Bus {
public:
Bus(uint8_t *ram,
@ -21,8 +21,7 @@ namespace nes {
Ppu *ppu,
Cartridge *cartridge,
Controller *controller1,
Controller *controller2,
Dma *dma);
Controller *controller2);
void connectCartridge(Cartridge *cartridge);
void connectController1(Controller *controller1);
@ -42,7 +41,6 @@ namespace nes {
Cartridge* _cartridge;
Controller* _controller1;
Controller* _controller2;
Dma* _dma;
};
}

21
src/Cpu.cpp
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@ -6,10 +6,6 @@
#include "Bus.h"
#include <iostream>
#ifdef NES_LOGGING
#include <fmt/format.h>
#endif
namespace nes {
Cpu::Cpu(): _ticks{}, A{}, X{}, Y{}, PC{}, SP{}, flags{} {
@ -229,23 +225,6 @@ namespace nes {
_bus = bus;
}
#ifdef NES_LOGGING
std::string Cpu::state() const {
return fmt::format("{} ({:02X}), PC: {:X}, SP: {:X}, A: {:02X}, X: {:02X}, Y: {:02X}, [N:{}, V:{}, B{}, D{}, I{}, Z:{}, C:{}], H: {:08X}",
_instructions[_currentOpcode].name,
_currentOpcode,
PC, SP, A, X, Y,
(int)getFlag(Negative),
(int)getFlag(Overflow),
(int)getFlag(Break),
(int)getFlag(DecimalMode),
(int)getFlag(InterruptDisable),
(int)getFlag(Zero),
(int)getFlag(Carry),
_bus->zpHash());
}
#endif
void Cpu::setFlag(CpuFlags flag, bool value) {
if(value) {
flags |= flag;

4
src/Cpu.h
View File

@ -50,10 +50,6 @@ namespace nes {
void setStartAddress(uint16_t address);
void nmi();
void connectToBus(Bus* bus);
#ifdef NES_LOGGING
std::string state() const;
#endif
private:
size_t _ticks;

47
src/Dma.cpp
View File

@ -1,47 +0,0 @@
//
// Created by selim on 9/23/23.
//
#include "Dma.h"
#include "Ppu.h"
#include "Bus.h"
namespace nes {
Dma::Dma(Ppu *ppu): _ppu{ppu} {
}
bool Dma::active() const {
return _active;
}
void Dma::tick(uint64_t cycles) {
if(_dummy) {
if(cycles % 2 == 1) {
_dummy = false;
}
} else {
if(cycles % 2 == 0) {
_data = _bus->read((_page << 8) | _address);
} else {
_ppu->writeOam(_address, _data);
_address++;
if(_address == 0) {
_active = false;
_dummy = true;
}
}
}
}
void Dma::start(uint8_t page) {
_page = page;
_active = true;
}
void Dma::connectToBus(Bus *bus) {
_bus = bus;
}
}

39
src/Dma.h
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@ -1,39 +0,0 @@
//
// Created by selim on 9/23/23.
//
#ifndef NES_DMA_H
#define NES_DMA_H
#include <cstdint>
namespace nes {
class Bus;
class Ppu;
class Dma {
public:
Dma(Ppu* ppu);
[[nodiscard]] bool active() const;
void tick(uint64_t cycles);
void start(uint8_t page);
void connectToBus(Bus *bus);
private:
Bus* _bus;
Ppu* _ppu;
private:
uint8_t _page = 0;
uint8_t _address = 0;
uint8_t _data = 0;
private:
bool _active = false;
bool _dummy = true;
};
}
#endif //NES_DMA_H

4
src/Logger.cpp
View File

@ -6,7 +6,7 @@
#include <cstring>
#include <fstream>
#include <fmt/format.h>
#include <format>
namespace nes {
@ -19,7 +19,7 @@ namespace nes {
return;
}
std::string cycleString = fmt::format("[{:06d}] ", cycle);
std::string cycleString = std::format("[{:06d}] ", cycle);
std::memcpy(_data.get() + _offset, cycleString.data(), cycleString.size());
_offset += cycleString.size();

39
src/Oam.cpp
View File

@ -6,6 +6,7 @@
#include "Ppu.h"
#include <cstring>
#include <print>
namespace nes {
@ -25,10 +26,6 @@ namespace nes {
_address++;
}
void Oam::write(uint8_t address, uint8_t value) {
reinterpret_cast<uint8_t*>(_data)[address] = value;
}
bool Oam::detectVisibleSprites(int16_t scanline, bool bigSprite) {
memset(_visibleSprites, 0xFF, MAX_SPRITES_PER_SCANLINE*sizeof(SpriteInfo));
_visibleSpriteCount = 0;
@ -142,4 +139,36 @@ namespace nes {
bool Oam::spriteZeroBeingRendered() const {
return _spriteZeroVisible && _firstVisibleSpriteBeingRendered;
}
}
void Oam::dmaTick(uint64_t cycles) {
if(_dmaDummy) {
if(cycles % 2 == 1) {
_dmaDummy = false;
}
} else {
if(cycles % 2 == 0) {
_dmaData = _ppu->readRam((_dmaPage << 8) | _dmaAddress++);
} else {
write(_dmaData);
if(_dmaAddress == 0) {
_dmaActive = false;
_dmaDummy = true;
}
}
}
}
void Oam::dmaStart(uint8_t page) {
_dmaPage = page;
_dmaAddress = 0;
_dmaActive = true;
}
bool Oam::dmaActive() const {
return _dmaActive;
}
uint8_t Oam::address() const {
return _address;
}
}

12
src/Oam.h
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@ -38,7 +38,10 @@ namespace nes {
void setAddress(uint8_t address);
[[nodiscard]] uint8_t read() const;
void write(uint8_t value);
void write(uint8_t address, uint8_t value);
void dmaTick(uint64_t cycles);
void dmaStart(uint8_t page);
bool dmaActive() const;
uint8_t address() const;
public:
bool detectVisibleSprites(int16_t scanline, bool bigSprite);
@ -59,6 +62,13 @@ namespace nes {
uint8_t _visibleSpriteCount = 0;
bool _spriteZeroVisible = false;
bool _firstVisibleSpriteBeingRendered = false;
private:
uint8_t _dmaPage = 0;
uint8_t _dmaAddress = 0;
uint8_t _dmaData = 0;
bool _dmaActive = false;
bool _dmaDummy = true;
};
}

53
src/Ppu.cpp
View File

@ -3,11 +3,6 @@
//
#include "Ppu.h"
#ifdef NES_LOGGING
#include <fmt/format.h>
#endif
#include <print>
namespace nes {
@ -185,6 +180,8 @@ namespace nes {
case OamData:
value = _oam->read();
break;
case OamAddress:
value = _oam->address();
}
return value;
}
@ -338,6 +335,22 @@ namespace nes {
}
}
uint8_t Ppu::readRam(uint16_t address) const {
return _bus->read(address);
}
bool Ppu::dmaActive() const {
return _oam->dmaActive();
}
void Ppu::dmaTick(uint64_t cycles) const {
_oam->dmaTick(cycles);
}
void Ppu::startDma(uint8_t page) const {
_oam->dmaStart(page);
}
Pixel Ppu::getColor(uint8_t palette, uint8_t pixel) {
uint16_t address = 0x3F00 + palette*4 + pixel;
return _palette[internalRead(address) & 0x3F];
@ -432,33 +445,7 @@ namespace nes {
}
}
#ifdef NES_LOGGING
std::string Ppu::state() const {
auto palettes = (uint32_t*)_paletteTable.get();
return fmt::format("X:{:03d}, Y:{:03d}, V:{:d}, vR: [CX:{:02X}, CY:{:02X}, NX:{:d}, NY:{:d}, FY:{:d}], tR: [CX:{:02X}, CY:{:02X}, NX:{:d}, NY:{:d}, FY:{:d}], FX:{:d}, AL:{:d}, ASL:{:04X}, ASH:{:04X}",
_column,
_scanline,
_status.verticalBlank,
_vRamAddress.coarseX,
_vRamAddress.coarseY,
_vRamAddress.nameTableX,
_vRamAddress.nameTableY,
_vRamAddress.fineY,
_tRamAddress.coarseX,
_tRamAddress.coarseY,
_tRamAddress.nameTableX,
_tRamAddress.nameTableY,
_tRamAddress.fineY,
_fineX,
_addressWriteInProgress,
_bgAttribShifter._lo,
_bgAttribShifter._hi);
}
#endif
void Ppu::writeOam(uint8_t address, uint8_t data) {
_oam->write(address, data);
void Ppu::writeOam(uint8_t data) {
_oam->write(data);
}
}

10
src/Ppu.h
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@ -107,13 +107,13 @@ namespace nes {
void setPixel(uint16_t row, uint16_t column, Pixel pixel);
void connectToBus(Bus* bus);
void reset();
void writeOam(uint8_t address, uint8_t data);
void writeOam(uint8_t data);
uint8_t internalRead(uint16_t address);
void internalWrite(uint16_t address, uint8_t value);
#ifdef NES_LOGGING
[[nodiscard]] std::string state() const;
#endif
[[nodiscard]] uint8_t readRam(uint16_t address) const;
[[nodiscard]] bool dmaActive() const;
void dmaTick(uint64_t cycles) const;
void startDma(uint8_t page) const;
public:
std::function<void(const Pixel*)> onNewFrame;

34
src/System.cpp
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@ -9,28 +9,20 @@
#include "Controller.h"
#include <utility>
#include <iostream>
namespace nes {
System::System():
_cycles{}
#ifdef NES_LOGGING
,_logger(500*1024*1024)
#endif
{
System::System(): _cycles{} {
_ram = std::make_unique<uint8_t[]>(2*1024);
_cpu = std::make_unique<Cpu>();
_ppu = std::make_unique<Ppu>();
_dma = std::make_unique<Dma>(_ppu.get());
_controller1 = std::make_shared<Controller>();
_bus = std::make_unique<Bus>(_ram.get(),
_cpu.get(),
_ppu.get(),
_cartridge.get(),
_controller1.get(),
nullptr,
_dma.get());
nullptr);
}
void System::insertCartridge(const fs::path &path, std::optional<uint16_t> address) {
@ -58,37 +50,19 @@ namespace nes {
void System::tick() {
bool needInterrupt = _ppu->tick();
#ifdef NES_LOGGING
_logger.addLine(_cycles, _ppu->state());
#endif
if(_cycles % 3 == 0) {
if(_dma->active()) {
_dma->tick(_cycles);
if(_ppu->dmaActive()) {
_ppu->dmaTick(_cycles);
} else {
bool instructionExecuted = _cpu->tick();
#ifdef NES_LOGGING
if(instructionExecuted) {
_logger.addLine(_cycles, _cpu->state());
}
#endif
}
}
if(needInterrupt) {
_cpu->nmi();
#ifdef NES_LOGGING
_logger.addLine(_cycles, "NMI");
_logger.addLine(_cycles, _cpu->state());
#endif
}
#ifdef NES_LOGGING
if(_cycles == 3000000) {
_logger.dump("/home/selim/Documents/log.txt");
}
#endif
_cycles++;
}

6
src/System.h
View File

@ -9,7 +9,6 @@
#include "Cpu.h"
#include "Ppu.h"
#include "Cartridge.h"
#include "Dma.h"
#include "Bus.h"
#include <filesystem>
@ -40,12 +39,7 @@ namespace nes {
std::unique_ptr<Ppu> _ppu;
std::unique_ptr<Cartridge> _cartridge;
std::shared_ptr<Controller> _controller1;
std::unique_ptr<Dma> _dma;
std::unique_ptr<Bus> _bus;
#ifdef NES_LOGGING
Logger _logger;
#endif
};
}