Files
ci-libretro-fceumm/src/boards/14.c
2025-09-12 21:59:27 +02:00

102 lines
2.5 KiB
C

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2023
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "mapinc.h"
#include "asic_mmc3.h"
#include "asic_vrc2and4.h"
static uint8 reg;
static uint8 init; /* Games switch between ASICs expecting registers to keep their value, so initialize each ASIC only on the first switch and use this bitfield to track it */
static void applyMode (uint8);
static SFORMAT StateRegs[] = {
{ &reg, 1, "MODE" },
{ &init, 1, "INIT" },
{ 0 },
};
static void sync (void) {
if (reg &0x02) {
MMC3_syncPRG(0x3F, 0x00);
MMC3_syncCHR(0x1FF, 0x00);
MMC3_syncMirror();
} else {
VRC24_syncPRG(0x3F, 0x00);
VRC24_syncCHR(0x1FF, 0x00);
VRC24_syncMirror();
}
}
int getCHRBank_MMC3 (uint8 bank) {
return MMC3_getCHRBank(bank) | reg <<(~bank &4? 5: ~bank &2? 3: 1) &0x100;
}
int getCHRBank_VRC2 (uint8 bank) {
return VRC24_getCHRBank(bank) | reg <<(~bank &4? 5: ~bank &2? 3: 1) &0x100;
}
static DECLFW (writeReg) {
uint8 previousReg = reg;
reg = V;
if ((previousReg ^V) &2)
applyMode(1);
else
sync();
}
static void applyMode (uint8 clear) {
PPU_hook = NULL;
MapIRQHook = NULL;
GameHBIRQHook = NULL;
if (reg &0x02) {
MMC3_activate(clear && init &1, sync, MMC3_TYPE_AX5202P, NULL, getCHRBank_MMC3, NULL, NULL);
init &= ~1;
} else {
VRC2_activate(clear && init &2, sync, 0x01, 0x02, NULL, getCHRBank_VRC2, NULL, NULL);
init &= ~2;
}
SetWriteHandler(0xA131, 0xA131, writeReg);
}
static void reset (void) {
reg = 0;
init = 3;
applyMode(1);
}
static void power (void) {
reg = 0;
init = 3;
applyMode(1);
}
static void restore (int version) {
applyMode(0);
}
void UNLSL1632_Init (CartInfo *info) {
MMC3_addExState();
VRC24_addExState();
info->Reset = reset;
info->Power = power;
GameStateRestore = restore;
AddExState(StateRegs, ~0, 0, 0);
}