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GB: Start MBCs

This commit is contained in:
Jeffrey Pfau 2016-01-16 21:29:09 -08:00
parent 7c989fd818
commit b711432a5e
3 changed files with 163 additions and 3 deletions
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24
src/gb/gb.h
View File

@ -52,6 +52,30 @@ struct GB {
const char* activeFile;
};
struct GBCartridge {
uint8_t entry[4];
uint8_t logo[48];
union {
char titleLong[16];
struct {
char titleShort[11];
char maker[4];
uint8_t cgb;
};
};
char licensee[2];
uint8_t sgb;
uint8_t type;
uint8_t romSize;
uint8_t ramSize;
uint8_t region;
uint8_t oldLicensee;
uint8_t version;
uint8_t headerChecksum;
uint16_t globalChecksum;
// And ROM data...
};
void GBCreate(struct GB* gb);
void GBDestroy(struct GB* gb);

125
src/gb/memory.c
View File

@ -10,6 +10,19 @@
#include "util/memory.h"
static void _GBMBCNone(struct GBMemory* memory, uint16_t address, uint8_t value) {
// TODO: Log game error
UNUSED(memory);
UNUSED(address);
UNUSED(value);
}
static void _GBMBC1(struct GBMemory*, uint16_t address, uint8_t value);
static void _GBMBC2(struct GBMemory*, uint16_t address, uint8_t value);
static void _GBMBC3(struct GBMemory*, uint16_t address, uint8_t value);
static void _GBMBC4(struct GBMemory*, uint16_t address, uint8_t value);
static void _GBMBC5(struct GBMemory*, uint16_t address, uint8_t value);
static void GBSetActiveRegion(struct LR35902Core* cpu, uint16_t address) {
// TODO
}
@ -27,6 +40,8 @@ void GBMemoryInit(struct GB* gb) {
gb->memory.rom = 0;
gb->memory.romBank = 0;
gb->memory.romSize = 0;
gb->memory.mbcType = GB_MBC_NONE;
gb->memory.mbc = 0;
memset(gb->memory.hram, 0, sizeof(gb->memory.hram));
@ -48,6 +63,52 @@ void GBMemoryReset(struct GB* gb) {
gb->memory.wramBank = &gb->memory.wram[GB_SIZE_WORKING_RAM_BANK0];
gb->memory.romBank = &gb->memory.rom[GB_SIZE_CART_BANK0];
const struct GBCartridge* cart = &gb->memory.rom[0x100];
switch (cart->type) {
case 0:
case 8:
case 9:
gb->memory.mbc = _GBMBCNone;
gb->memory.mbcType = GB_MBC_NONE;
break;
case 1:
case 2:
case 3:
gb->memory.mbc = _GBMBC1;
gb->memory.mbcType = GB_MBC1;
break;
case 5:
case 6:
gb->memory.mbc = _GBMBC2;
gb->memory.mbcType = GB_MBC2;
break;
case 0x0F:
case 0x10:
case 0x11:
case 0x12:
case 0x13:
gb->memory.mbc = _GBMBC3;
gb->memory.mbcType = GB_MBC3;
break;
case 0x15:
case 0x16:
case 0x17:
gb->memory.mbc = _GBMBC4;
gb->memory.mbcType = GB_MBC4;
break;
default:
// TODO: Log
case 0x19:
case 0x1A:
case 0x1B:
case 0x1C:
case 0x1D:
case 0x1E:
gb->memory.mbc = _GBMBC5;
gb->memory.mbcType = GB_MBC5;
break;
}
if (!gb->memory.wram) {
GBMemoryDeinit(gb);
}
@ -114,13 +175,11 @@ void GBStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
case GB_REGION_CART_BANK0 + 1:
case GB_REGION_CART_BANK0 + 2:
case GB_REGION_CART_BANK0 + 3:
// TODO
return;
case GB_REGION_CART_BANK1:
case GB_REGION_CART_BANK1 + 1:
case GB_REGION_CART_BANK1 + 2:
case GB_REGION_CART_BANK1 + 3:
// TODO
memory->mbc(memory, address, value);
return;
case GB_REGION_VRAM:
case GB_REGION_VRAM + 1:
@ -157,3 +216,63 @@ uint8_t GBView8(struct LR35902Core* cpu, uint16_t address);
void GBPatch16(struct LR35902Core* cpu, uint16_t address, int16_t value, int16_t* old);
void GBPatch8(struct LR35902Core* cpu, uint16_t address, int8_t value, int8_t* old);
static void _switchBank(struct GBMemory* memory, int bank) {
size_t bankStart = bank * GB_SIZE_CART_BANK0;
if (bankStart + GB_SIZE_CART_BANK0 > memory->romSize) {
// TODO: Log
return;
}
memory->romBank = &memory->rom[bankStart];
memory->currentBank = bank;
}
void _GBMBC1(struct GBMemory* memory, uint16_t address, uint8_t value) {
int bank = value & 0x1F;
switch (address >> 13) {
case 0x0:
// TODO
break;
case 0x1:
if (!bank) {
++bank;
}
_switchBank(memory, bank | (memory->currentBank & 0x60));
break;
}
}
void _GBMBC2(struct GBMemory* memory, uint16_t address, uint8_t value) {
// TODO
}
void _GBMBC3(struct GBMemory* memory, uint16_t address, uint8_t value) {
int bank = value & 0x7F;
switch (address >> 13) {
case 0x0:
// TODO
break;
case 0x1:
if (!bank) {
++bank;
}
_switchBank(memory, bank);
break;
}
}
void _GBMBC4(struct GBMemory* memory, uint16_t address, uint8_t value) {
// TODO
}
void _GBMBC5(struct GBMemory* memory, uint16_t address, uint8_t value) {
int bank = value & 0x7F;
switch (address >> 13) {
case 0x0:
// TODO
break;
case 0x1:
_switchBank(memory, bank);
break;
}
}

17
src/gb/memory.h
View File

@ -47,9 +47,26 @@ enum {
GB_SIZE_HRAM = 0x7F,
};
enum GBMemoryBankControllerType {
GB_MBC_NONE = 0,
GB_MBC1 = 1,
GB_MBC2 = 2,
GB_MBC3 = 3,
GB_MBC4 = 4,
GB_MBC5 = 5,
GB_MMM01 = 0x10,
GB_HuC1 = 0x11
};
struct GBMemory;
typedef void (*GBMemoryBankController)(struct GBMemory*, uint16_t address, uint8_t value);
struct GBMemory {
uint8_t* rom;
uint8_t* romBank;
enum GBMemoryBankControllerType mbcType;
GBMemoryBankController mbc;
int currentBank;
uint8_t* wram;
uint8_t* wramBank;