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added cartridge loading

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This commit is contained in:
Lauchmelder 2021-10-20 23:11:08 +02:00
parent 5aa8a64871
commit abb9b2e54a
5 changed files with 68 additions and 6 deletions
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53
NES Emulator/cartridge.c
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@ -4,6 +4,33 @@
#include "bus.h"
struct INES_Header
{
Byte nestext[4];
Byte prg_rom_size;
Byte chr_rom_size;
struct
{
Byte mirror : 1;
Byte battery : 1;
Byte trainer : 1;
Byte ignore_mirror : 1;
Byte mapper_lower_nibble : 4;
} Flags6;
struct
{
Byte vs : 1;
Byte playchoice : 1;
Byte nes20 : 2;
Byte mapper_upper_nibble : 4;
} Flags7;
Byte prg_ram_size;
Byte unused[7];
};
struct Cartridge* createCartridge(struct Bus* parent, const char* filepath)
{
struct Cartridge* cartridge = (struct Cartridge*)malloc(sizeof(struct Cartridge));
@ -13,13 +40,35 @@ struct Cartridge* createCartridge(struct Bus* parent, const char* filepath)
exit(1);
}
cartridge->memory = NULL;
// Open ROM
FILE* fp = fopen(filepath, "rb");
// Read header
struct INES_Header header;
fread(&header, sizeof(header), 1, fp);
cartridge->prg_rom = (Byte*)malloc(0x4000 * (size_t)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)header.chr_rom_size);
if (cartridge->prg_rom == NULL)
{
fprintf(stderr, "Failed to allocate CHR memory for cartridge, aborting.\n");
exit(1);
}
cartridge->bus = parent;
return cartridge;
}
void destroyCartridge(struct Cartridge* cartridge)
{
// free(cartridge->memory);
free(cartridge->chr_rom);
free(cartridge->prg_rom);
free(cartridge);
}