From 19d138fb5f95c1e30c34e050d8f4c00a87fea152 Mon Sep 17 00:00:00 2001
From: Lauchmelder <robert.trololo@gmail.com>
Date: Sat, 23 Oct 2021 19:30:02 +0200
Subject: [PATCH] added ppu
---
NES Emulator/CMakeLists.txt | 2 +-
NES Emulator/bus.c | 10 +++-
NES Emulator/bus.h | 2 +
NES Emulator/log.c | 9 +++-
NES Emulator/ppu.c | 101 ++++++++++++++++++++++++++++++++++++
NES Emulator/ppu.h | 95 +++++++++++++++++++++++++++++++++
6 files changed, 216 insertions(+), 3 deletions(-)
create mode 100644 NES Emulator/ppu.c
create mode 100644 NES Emulator/ppu.h
diff --git a/NES Emulator/CMakeLists.txt b/NES Emulator/CMakeLists.txt
index 79888f4..f37c02f 100644
--- a/NES Emulator/CMakeLists.txt
+++ b/NES Emulator/CMakeLists.txt
@@ -1,6 +1,6 @@
cmake_minimum_required (VERSION 3.8)
-add_executable (nesemu "main.c" "cpu.h" "types.h" "bus.h" "bus.c" "cartridge.h" "cpu.c" "cartridge.c" "opcodes.c" "log.c")
+add_executable (nesemu "main.c" "cpu.h" "types.h" "bus.h" "bus.c" "cartridge.h" "cpu.c" "cartridge.c" "opcodes.c" "log.c" "ppu.h" "ppu.c")
if(MSVC)
target_compile_definitions(nesemu PUBLIC _CRT_SECURE_NO_WARNINGS)
diff --git a/NES Emulator/bus.c b/NES Emulator/bus.c
index 9144e5a..19b8a63 100644
--- a/NES Emulator/bus.c
+++ b/NES Emulator/bus.c
@@ -4,6 +4,7 @@
#include <memory.h>
#include "cpu.h"
+#include "ppu.h"
#include "cartridge.h"
struct Bus* createBus()
@@ -35,6 +36,9 @@ struct Bus* createBus()
// Create CPU and attach it
bus->cpu = createCPU(bus);
+ // Create PPU and attack it
+ bus->ppu = createPPU(bus);
+
// Create and insert cartridge
bus->cartridge = createCartridge(bus, "roms/nestest.nes");
@@ -46,6 +50,7 @@ struct Bus* createBus()
void destroyBus(struct Bus* bus)
{
destroyCartridge(bus->cartridge);
+ destroyPPU(bus->ppu);
destroyCPU(bus->cpu);
free(bus->io);
@@ -104,5 +109,8 @@ void writeBus(struct Bus* bus, Word addr, Byte val)
void tick(struct Bus* bus)
{
- tickInstr(bus->cpu);
+ for (int i = 0; i < 3; i++)
+ tickPPU(bus->ppu);
+
+ tickCPU(bus->cpu);
}
\ No newline at end of file
diff --git a/NES Emulator/bus.h b/NES Emulator/bus.h
index ceafd6a..e9b2d39 100644
--- a/NES Emulator/bus.h
+++ b/NES Emulator/bus.h
@@ -4,6 +4,7 @@
#include "types.h"
struct CPU;
+struct PPU;
struct Cartridge;
// Main communication path for devices and memory in the NES
@@ -13,6 +14,7 @@ struct Bus
Byte* io;
struct CPU* cpu;
+ struct PPU* ppu;
struct Cartridge* cartridge;
};
diff --git a/NES Emulator/log.c b/NES Emulator/log.c
index eb96188..c373f88 100644
--- a/NES Emulator/log.c
+++ b/NES Emulator/log.c
@@ -3,6 +3,7 @@
#include <stdio.h>
#include "bus.h"
#include "cpu.h"
+#include "ppu.h"
void logBusState(struct Bus* bus)
{
@@ -40,5 +41,11 @@ void logBusState(struct Bus* bus)
printf("%-28s", buffer);
- printf("A:%02X X:%02X Y:%02X SP:%02X P:%02X CYC:%zu\n", bus->cpu->acc, bus->cpu->x, bus->cpu->y, bus->cpu->sp, bus->cpu->status.raw, bus->cpu->totalCycles);
+ printf("A:%02X X:%02X Y:%02X SP:%02X P:%02X PPU:%3d,%3d CYC:%zu\n",
+ bus->cpu->acc,
+ bus->cpu->x, bus->cpu->y,
+ bus->cpu->sp,
+ bus->cpu->status.raw,
+ bus->ppu->y, bus->ppu->x,
+ bus->cpu->totalCycles);
}
\ No newline at end of file
diff --git a/NES Emulator/ppu.c b/NES Emulator/ppu.c
new file mode 100644
index 0000000..c9a1cbd
--- /dev/null
+++ b/NES Emulator/ppu.c
@@ -0,0 +1,101 @@
+#include "ppu.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <memory.h>
+#include "bus.h"
+
+struct PPU* createPPU(struct Bus* parent)
+{
+ struct PPU* ppu = (struct PPU*)malloc(sizeof(struct PPU));
+ if (ppu == NULL)
+ {
+ fprintf(stderr, "Failed to allocate memory for PPU object.\n");
+ exit(1);
+ }
+
+ ppu->bus = parent;
+
+ for (int i = 0; i < 2; i++)
+ {
+ ppu->patternTables[i] = (Byte*)malloc(0x1000);
+ if (ppu->patternTables[i] == NULL)
+ {
+ fprintf(stderr, "Failed to allocate memory for PPU pattern table #%d object.\n", i);
+ exit(1);
+ }
+
+ memset(ppu->patternTables[i], 0, 0x1000);
+ }
+
+ for (int i = 0; i < 4; i++)
+ {
+ ppu->nametables[i] = (Byte*)malloc(0x0400);
+ if (ppu->nametables[i] == NULL)
+ {
+ fprintf(stderr, "Failed to allocate memory for PPU nametable #%d object.\n", i);
+ exit(1);
+ }
+
+ memset(ppu->nametables[i], 0, 0x0400);
+ }
+
+ ppu->paletteIndexes = (Byte*)malloc(0x20);
+ if (ppu->paletteIndexes == NULL)
+ {
+ fprintf(stderr, "Failed to allocate memory for PPU palette RAM indexes.\n");
+ exit(1);
+ }
+
+ ppu->oam = (Byte*)malloc(0x100);
+ if (ppu->oam == NULL)
+ {
+ fprintf(stderr, "Failed to allocate memory for PPU OAM.\n");
+ exit(1);
+ }
+
+ ppu->ppuctrl.raw = 0b00000000;
+ ppu->ppumask.raw = 0b00000000;
+ ppu->ppustatus.raw = 0b10100000;
+ ppu->oamaddr = 0x00;
+ ppu->ppuAddr = 0x00;
+ ppu->ppuData = 0x00;
+
+ ppu->x = 0;
+ ppu->y = 0;
+
+ return ppu;
+}
+
+void destroyPPU(struct PPU* ppu)
+{
+ free(ppu->oam);
+ free(ppu->paletteIndexes);
+ free(ppu->nametables);
+ free(ppu->patternTables);
+
+ free(ppu);
+}
+
+Byte ppuRead(struct PPU* ppu, Word addr)
+{
+ return 0x00;
+}
+
+void ppuWrite(struct PPU* ppu, Word addr, Byte val)
+{
+}
+
+void tickPPU(struct PPU* ppu)
+{
+ ppu->x++;
+
+ if (ppu->x == 341)
+ {
+ ppu->x = 0;
+ ppu->y++;
+
+ if (ppu->y == 261)
+ ppu->y = 0;
+ }
+}
diff --git a/NES Emulator/ppu.h b/NES Emulator/ppu.h
new file mode 100644
index 0000000..91ee4dd
--- /dev/null
+++ b/NES Emulator/ppu.h
@@ -0,0 +1,95 @@
+#ifndef _PPU_H_
+#define _PPU_H_
+
+#include "types.h"
+
+struct Bus;
+
+struct PPU
+{
+ // REGISTERS
+ union
+ {
+ struct
+ {
+ Byte nametable : 2;
+ Byte increment : 1;
+ Byte spriteTile : 1;
+ Byte bgTile : 1;
+ Byte spriteHeight : 1;
+ Byte master : 1;
+ Byte nmiEnable : 1;
+ };
+
+ Byte raw;
+
+ } ppuctrl;
+
+ union
+ {
+ struct
+ {
+ Byte greyscale : 1;
+ Byte bgLeftColumn : 1;
+ Byte spriteLeftColumn : 1;
+ Byte bgEnable : 1;
+ Byte spriteEnable : 1;
+ Byte colorEmphasis : 3;
+ };
+
+ Byte raw;
+
+ } ppumask;
+
+ union
+ {
+ struct
+ {
+ Byte padding : 5;
+ Byte overflow : 1;
+ Byte spriteZeroHit : 1;
+ Byte vBlank : 1;
+ };
+
+ Byte raw;
+
+ } ppustatus;
+
+ Byte oamaddr;
+ Byte oamdata;
+ Byte ppuScroll;
+ Byte ppuAddr;
+ Byte ppuData;
+ Byte oamdma;
+
+ Byte* patternTables[2];
+ Byte* nametables[4];
+ Byte* paletteIndexes;
+
+ union
+ {
+ struct
+ {
+ Byte y;
+ Byte tile;
+ Byte attr;
+ Byte x;
+ };
+
+ DWord raw;
+ }* oam;
+
+ Word x, y;
+
+ struct Bus* bus;
+};
+
+struct PPU* createPPU(struct Bus* parent);
+void destroyPPU(struct PPU* ppu);
+
+Byte ppuRead(struct PPU* ppu, Word addr);
+void ppuWrite(struct PPU* ppu, Word addr, Byte val);
+
+void tickPPU(struct PPU* ppu);
+
+#endif // _PPU_H_
\ No newline at end of file