NESEmulator/NES Emulator/cartridge.c
2021-10-24 13:47:11 +02:00

80 lines
1.8 KiB
C

#include "cartridge.h"
#include <stdlib.h>
#include <stdio.h>
#include "bus.h"
struct Cartridge* createCartridge(struct Bus* parent, const char* filepath)
{
struct Cartridge* cartridge = (struct Cartridge*)malloc(sizeof(struct Cartridge));
if (cartridge == NULL)
{
fprintf(stderr, "Failed to create cartridge.\n");
exit(1);
}
FILE* fp = fopen(filepath, "rb");
fread(&cartridge->header, sizeof(cartridge->header), 1, fp);
cartridge->prg_rom = (Byte*)malloc(0x4000 * (size_t)cartridge->header.prg_rom_size);
if (cartridge->prg_rom == NULL)
{
fprintf(stderr, "Failed to allocate PRG memory for cartridge, aborting.\n");
exit(1);
}
cartridge->chr_rom = (Byte*)malloc(0x2000 * (size_t)cartridge->header.chr_rom_size);
if (cartridge->chr_rom == NULL)
{
fprintf(stderr, "Failed to allocate CHR memory for cartridge, aborting.\n");
exit(1);
}
fread(cartridge->prg_rom, 0x4000, cartridge->header.prg_rom_size, fp);
fread(cartridge->chr_rom, 0x2000, cartridge->header.chr_rom_size, fp);
cartridge->bus = parent;
return cartridge;
}
void destroyCartridge(struct Cartridge* cartridge)
{
free(cartridge->chr_rom);
free(cartridge->prg_rom);
free(cartridge);
}
Byte readCartridge(struct Cartridge* cartridge, Word addr)
{
// TODO: Force M000 mapper for now
Byte val = 0;
if (0x6000 <= addr && addr <= 0x7FFF) // PRG RAM
{
// do nothing for now
}
else if (0x8000 <= addr && addr <= 0xFFFF) // PRG ROM
{
val = cartridge->prg_rom[addr % 0x4000];
}
return val;
}
void writeCartridge(struct Cartridge* cartridge, Word addr, Byte val)
{
// TODO: Force M000 mapper for now
if (0x6000 <= addr && addr <= 0x7FFF) // PRG RAM
{
// do nothing for now
}
else if (0x8000 <= addr && addr <= 0xFFFF) // PRG ROM
{
cartridge->prg_rom[addr % 0x4000] = val;
}
}