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SameBoy/Core/mbc.c
Lior Halphon 5c17c0ec3b unreachable fun
2022-01-03 17:17:35 +02:00

209 lines
8.3 KiB
C
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#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include "gb.h"
const GB_cartridge_t GB_cart_defs[256] = {
// From http://gbdev.gg8.se/wiki/articles/The_Cartridge_Header#0147_-_Cartridge_Type
/* MBC SUBTYPE RAM BAT. RTC RUMB. */
{ GB_NO_MBC, GB_STANDARD_MBC, false, false, false, false}, // 00h ROM ONLY
{ GB_MBC1 , GB_STANDARD_MBC, false, false, false, false}, // 01h MBC1
{ GB_MBC1 , GB_STANDARD_MBC, true , false, false, false}, // 02h MBC1+RAM
{ GB_MBC1 , GB_STANDARD_MBC, true , true , false, false}, // 03h MBC1+RAM+BATTERY
[5] =
{ GB_MBC2 , GB_STANDARD_MBC, true , false, false, false}, // 05h MBC2
{ GB_MBC2 , GB_STANDARD_MBC, true , true , false, false}, // 06h MBC2+BATTERY
[8] =
{ GB_NO_MBC, GB_STANDARD_MBC, true , false, false, false}, // 08h ROM+RAM
{ GB_NO_MBC, GB_STANDARD_MBC, true , true , false, false}, // 09h ROM+RAM+BATTERY
[0xB] =
/* Todo: Not supported yet */
{ GB_NO_MBC, GB_STANDARD_MBC, false, false, false, false}, // 0Bh MMM01
{ GB_NO_MBC, GB_STANDARD_MBC, false, false, false, false}, // 0Ch MMM01+RAM
{ GB_NO_MBC, GB_STANDARD_MBC, false, false, false, false}, // 0Dh MMM01+RAM+BATTERY
[0xF] =
{ GB_MBC3 , GB_STANDARD_MBC, false, true, true , false}, // 0Fh MBC3+TIMER+BATTERY
{ GB_MBC3 , GB_STANDARD_MBC, true , true, true , false}, // 10h MBC3+TIMER+RAM+BATTERY
{ GB_MBC3 , GB_STANDARD_MBC, false, false, false, false}, // 11h MBC3
{ GB_MBC3 , GB_STANDARD_MBC, true , false, false, false}, // 12h MBC3+RAM
{ GB_MBC3 , GB_STANDARD_MBC, true , true , false, false}, // 13h MBC3+RAM+BATTERY
[0x19] =
{ GB_MBC5 , GB_STANDARD_MBC, false, false, false, false}, // 19h MBC5
{ GB_MBC5 , GB_STANDARD_MBC, true , false, false, false}, // 1Ah MBC5+RAM
{ GB_MBC5 , GB_STANDARD_MBC, true , true , false, false}, // 1Bh MBC5+RAM+BATTERY
{ GB_MBC5 , GB_STANDARD_MBC, false, false, false, true }, // 1Ch MBC5+RUMBLE
{ GB_MBC5 , GB_STANDARD_MBC, true , false, false, true }, // 1Dh MBC5+RUMBLE+RAM
{ GB_MBC5 , GB_STANDARD_MBC, true , true , false, true }, // 1Eh MBC5+RUMBLE+RAM+BATTERY
[0x22] =
{ GB_MBC7 , GB_STANDARD_MBC, true, true, false, false}, // 22h MBC7+ACCEL+EEPROM
[0xFC] =
{ GB_MBC5 , GB_CAMERA , true , true , false, false}, // FCh POCKET CAMERA
{ GB_NO_MBC, GB_STANDARD_MBC, false, false, false, false}, // FDh BANDAI TAMA5 (Todo: Not supported)
{ GB_HUC3 , GB_STANDARD_MBC, true , true , true, false}, // FEh HuC3
{ GB_HUC1 , GB_STANDARD_MBC, true , true , false, false}, // FFh HuC1+RAM+BATTERY
};
void GB_update_mbc_mappings(GB_gameboy_t *gb)
{
switch (gb->cartridge_type->mbc_type) {
case GB_NO_MBC: return;
case GB_MBC1:
switch (gb->mbc1_wiring) {
case GB_STANDARD_MBC1_WIRING:
gb->mbc_rom_bank = gb->mbc1.bank_low | (gb->mbc1.bank_high << 5);
if (gb->mbc1.mode == 0) {
gb->mbc_ram_bank = 0;
gb->mbc_rom0_bank = 0;
}
else {
gb->mbc_ram_bank = gb->mbc1.bank_high;
gb->mbc_rom0_bank = gb->mbc1.bank_high << 5;
}
if ((gb->mbc_rom_bank & 0x1F) == 0) {
gb->mbc_rom_bank++;
}
break;
case GB_MBC1M_WIRING:
gb->mbc_rom_bank = (gb->mbc1.bank_low & 0xF) | (gb->mbc1.bank_high << 4);
if (gb->mbc1.mode == 0) {
gb->mbc_ram_bank = 0;
gb->mbc_rom0_bank = 0;
}
else {
gb->mbc_rom0_bank = gb->mbc1.bank_high << 4;
gb->mbc_ram_bank = 0;
}
if ((gb->mbc1.bank_low & 0x1F) == 0) {
gb->mbc_rom_bank++;
}
break;
nodefault;
}
break;
case GB_MBC2:
gb->mbc_rom_bank = gb->mbc2.rom_bank;
if ((gb->mbc_rom_bank & 0xF) == 0) {
gb->mbc_rom_bank = 1;
}
break;
case GB_MBC3:
gb->mbc_rom_bank = gb->mbc3.rom_bank;
gb->mbc_ram_bank = gb->mbc3.ram_bank;
if (!gb->is_mbc30) {
gb->mbc_rom_bank &= 0x7F;
}
if (gb->mbc_rom_bank == 0) {
gb->mbc_rom_bank = 1;
}
break;
case GB_MBC5:
gb->mbc_rom_bank = gb->mbc5.rom_bank_low | (gb->mbc5.rom_bank_high << 8);
gb->mbc_ram_bank = gb->mbc5.ram_bank;
break;
case GB_MBC7:
gb->mbc_rom_bank = gb->mbc7.rom_bank;
break;
case GB_HUC1:
if (gb->huc1.mode == 0) {
gb->mbc_rom_bank = gb->huc1.bank_low | (gb->mbc1.bank_high << 6);
gb->mbc_ram_bank = 0;
}
else {
gb->mbc_rom_bank = gb->huc1.bank_low;
gb->mbc_ram_bank = gb->huc1.bank_high;
}
break;
case GB_HUC3:
gb->mbc_rom_bank = gb->huc3.rom_bank;
gb->mbc_ram_bank = gb->huc3.ram_bank;
break;
case GB_TPP1:
gb->mbc_rom_bank = gb->tpp1.rom_bank;
gb->mbc_ram_bank = gb->tpp1.ram_bank;
gb->mbc_ram_enable = (gb->tpp1.mode == 2) || (gb->tpp1.mode == 3);
break;
nodefault;
}
}
void GB_configure_cart(GB_gameboy_t *gb)
{
gb->cartridge_type = &GB_cart_defs[gb->rom[0x147]];
if (gb->rom[0x147] == 0xbc &&
gb->rom[0x149] == 0xc1 &&
gb->rom[0x14a] == 0x65) {
static const GB_cartridge_t tpp1 = {GB_TPP1, GB_STANDARD_MBC, true, true, true, true};
gb->cartridge_type = &tpp1;
gb->tpp1.rom_bank = 1;
}
if (gb->rom[0x147] == 0 && gb->rom_size > 0x8000) {
GB_log(gb, "ROM header reports no MBC, but file size is over 32Kb. Assuming cartridge uses MBC3.\n");
gb->cartridge_type = &GB_cart_defs[0x11];
}
else if (gb->rom[0x147] != 0 && memcmp(gb->cartridge_type, &GB_cart_defs[0], sizeof(GB_cart_defs[0])) == 0) {
GB_log(gb, "Cartridge type %02x is not yet supported.\n", gb->rom[0x147]);
}
if (gb->mbc_ram) {
free(gb->mbc_ram);
gb->mbc_ram = NULL;
gb->mbc_ram_size = 0;
}
if (gb->cartridge_type->has_ram) {
if (gb->cartridge_type->mbc_type == GB_MBC2) {
gb->mbc_ram_size = 0x200;
}
else if (gb->cartridge_type->mbc_type == GB_MBC7) {
gb->mbc_ram_size = 0x100;
}
else if (gb->cartridge_type->mbc_type == GB_TPP1) {
if (gb->rom[0x152] >= 1 && gb->rom[0x152] <= 9) {
gb->mbc_ram_size = 0x2000 << (gb->rom[0x152] - 1);
}
}
else {
static const unsigned ram_sizes[256] = {0, 0x800, 0x2000, 0x8000, 0x20000, 0x10000};
gb->mbc_ram_size = ram_sizes[gb->rom[0x149]];
}
if (gb->mbc_ram_size) {
gb->mbc_ram = malloc(gb->mbc_ram_size);
}
/* Todo: Some games assume unintialized MBC RAM is 0xFF. It this true for all cartridge types? */
memset(gb->mbc_ram, 0xFF, gb->mbc_ram_size);
}
/* MBC1 has at least 3 types of wiring (We currently support two (Standard and 4bit-MBC1M) of these).
See http://forums.nesdev.com/viewtopic.php?f=20&t=14099 */
/* Attempt to "guess" wiring */
if (gb->cartridge_type->mbc_type == GB_MBC1) {
if (gb->rom_size >= 0x44000 && memcmp(gb->rom + 0x104, gb->rom + 0x40104, 0x30) == 0) {
gb->mbc1_wiring = GB_MBC1M_WIRING;
}
}
/* Detect MBC30 */
if (gb->cartridge_type->mbc_type == GB_MBC3) {
if (gb->rom_size > 0x200000 || gb->mbc_ram_size > 0x8000) {
gb->is_mbc30 = true;
}
}
/* Set MBC5's bank to 1 correctly */
if (gb->cartridge_type->mbc_type == GB_MBC5) {
gb->mbc5.rom_bank_low = 1;
}
/* Initial MBC7 state */
if (gb->cartridge_type->mbc_type == GB_MBC7) {
gb->mbc7.x_latch = gb->mbc7.y_latch = 0x8000;
gb->mbc7.latch_ready = true;
gb->mbc7.read_bits = -1;
gb->mbc7.eeprom_do = true;
}
}
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