YayIguess/GBpp
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

prelim mbc work

Browse Source
This commit is contained in:
Braiden Gent
2024-03-30 17:27:49 -07:00
parent 7854862850
commit 0bcf339ebf
9 changed files with 216 additions and 161 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
src/gameboy.hpp
View File

@@ -9,21 +9,7 @@
#include <vector>
#include <SDL.h>
#include "defines.hpp"
//two bits per colour
enum Colour {
black = 0b11,
darkGray = 0b10,
lightGray = 0b01,
white = 0b00
};
enum PPUMode {
mode0, // Horizontal Blank (Mode 0): No access to video RAM, occurs during horizontal blanking period.
mode1, // Vertical Blank (Mode 1): No access to video RAM, occurs during vertical blanking period.
mode2, // OAM Search (Mode 2): Access to OAM (Object Attribute Memory) only, sprite evaluation.
mode3 // Pixel Transfer (Mode 3): Access to both OAM and video RAM, actual pixel transfer to the screen.
};
#include "addressSpace.hpp"
union RegisterPair {
Word reg; //register.reg == (hi << 8) + lo. (hi is more significant than lo)
@@ -34,64 +20,6 @@ union RegisterPair {
};
};
class AddressSpace {
bool bootromLoaded = true;
Byte bootrom[BOOTROM_SIZE] = {0};
std::ifstream game;
public:
AddressSpace() {
// Initialize the memory to zero
memoryLayout = {};
std::memset(memoryLayout.memory, 0, sizeof(memoryLayout.memory));
}
// Nested union for the memory layout
union MemoryLayout {
Byte memory[0x10000];
struct {
Byte romBank1[ROM_BANK_SIZE]; // Mapped to 0x0000
Byte romBankSwitch[ROM_BANK_SIZE]; // Mapped to 0x4000
Byte vram[0x2000]; // Mapped to 0x8000
Byte externalRam[0x2000]; // Mapped to 0xA000
Byte memoryBank1[0x1000]; // Mapped to 0xC000
Byte memoryBank2[0x1000]; // Mapped to 0xD000
Byte echoRam[0x1E00]; // Mapped to 0xE000 (Echo RAM, mirrors 0xC000 to 0xDFFF)
Byte spriteAttributeTable[0xA0]; // Mapped to 0xFE00
Byte notUsable[0x60]; // Mapped to 0xFEA0
Byte io[0x80]; // Mapped to 0xFF00, 0xFF0F is interrupt flag
Byte specialRam[0x7F]; // Mapped to 0xFF80
Byte interuptEnableReg; // Mapped to 0xFFFF
};
} memoryLayout{};
void unmapBootrom();
void mapBootrom();
bool getBootromState() const;
void loadBootrom(const std::string& filename);
void loadGame(const std::string& filename);
//overload [] for echo ram and bootrom support
Byte operator[](const uint32_t address) const {
if (address >= 0xE000 && address < 0xFE00)
return memoryLayout.echoRam[address - 0x2000];
if (address < 0x0100 && bootromLoaded)
return bootrom[address];
return memoryLayout.memory[address];
}
Byte& operator[](const uint32_t address) {
if (address >= 0xE000 && address < 0xFE00)
return memoryLayout.echoRam[address - 0x2000];
if (address < 0x0100 && bootromLoaded)
return bootrom[address];
return memoryLayout.memory[address];
}
};
class GameBoy {
//T-cycles not M-cycles (4 T-cycles = 1 M-cycle)
uint64_t cycles = 0;
@@ -103,6 +31,7 @@ class GameBoy {
uint64_t lastScanline = 0;
uint64_t cyclesToStayInHblank = -1;
uint64_t lastDivUpdate = 0;
bool rendered = false;
uint8_t IME = 0; //enables interupts
@@ -120,7 +49,6 @@ class GameBoy {
//General purpose hardware registers
Byte* const JOYP = &addressSpace[0xFF00];
Byte* const SB = &addressSpace[0xFF01];
Byte* const SC = &addressSpace[0xFF02];
Byte* const DIV = &addressSpace[0xFF04];
@@ -223,6 +151,7 @@ class GameBoy {
//OPCODE FUNCTIONS
template <typename T>
void ld(T& dest, T src);
void ldW(Byte& dest, Word src);
template <typename T>
void orBitwise(T& dest, T src);
template <typename T>
@@ -249,8 +178,6 @@ class GameBoy {
void daa();
void stop();
template <typename T>
void ldW(T dest, T src);
template <typename T>
void cp(T value);
template <typename T>
void dec(T& reg);