mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-09-19 12:49:43 +02:00
f2e93d4949
added John Madden Football 93 in EEPROM database (fixes backup support) initiated ROM database for cartridges that uses SRAM (some ROM headers are definitively wrong !), need more...
297 lines
8.4 KiB
C
297 lines
8.4 KiB
C
/****************************************************************************
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* Genesis Plus
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* DATEL Action Replay / Pro Action Replay emulation
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*
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* Copyright (C) 2009 Eke-Eke (GCN/Wii port)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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***************************************************************************/
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#include "shared.h"
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#define TYPE_PRO1 0x12
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#define TYPE_PRO2 0x22
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static struct
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{
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uint8 enabled;
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uint8 rom[0x20000];
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uint8 ram[0x10000];
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uint16 regs[13];
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uint16 old[4];
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uint16 data[4];
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uint32 addr[4];
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} action_replay;
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static void wram_write_byte(uint32 address, uint32 data);
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static void wram_write_word(uint32 address, uint32 data);
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static void ar_write_regs(uint32 address, uint32 data);
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static void ar_write_regs_pro2(uint32 address, uint32 data);
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void datel_init(void)
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{
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memset(&action_replay,0,sizeof(action_replay));
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/* load Action Replay ROM program */
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FILE *f = fopen(AR_ROM,"rb");
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if (!f) return;
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int size = fread(action_replay.rom,1,0x20000,f);
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fclose(f);
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/* detect Action Replay yype */
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if (size < 0x10000)
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action_replay.enabled = TYPE_AR;
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else if (size < 0x20000)
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action_replay.enabled = TYPE_PRO2;
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else
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action_replay.enabled = TYPE_PRO1;
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/* default memory map */
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switch (action_replay.enabled)
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{
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case TYPE_AR:
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{
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/* internal registers mapped at $010000-$01ffff */
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m68k_memory_map[0x01].write16 = ar_write_regs;
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/* $0000-$7fff mirrored into $8000-$ffff */
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memcpy(action_replay.rom+0x8000,action_replay.rom,0x8000);
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break;
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}
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case TYPE_PRO1:
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{
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/* internal registers mapped at $010000-$01ffff */
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m68k_memory_map[0x01].write16 = ar_write_regs;
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/* RAM (64k) mapped at $420000-$42ffff */
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m68k_memory_map[0x42].base = action_replay.ram;
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m68k_memory_map[0x42].read8 = NULL;
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m68k_memory_map[0x42].read16 = NULL;
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m68k_memory_map[0x42].write8 = NULL;
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m68k_memory_map[0x42].write16 = NULL;
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break;
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}
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case TYPE_PRO2:
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{
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/* internal registers mapped at $100000-$10ffff */
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m68k_memory_map[0x10].write16 = ar_write_regs_pro2;
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/* RAM (64k) mapped at $600000-$60ffff */
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m68k_memory_map[0x60].base = action_replay.ram;
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m68k_memory_map[0x60].read8 = NULL;
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m68k_memory_map[0x60].read16 = NULL;
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m68k_memory_map[0x60].write8 = NULL;
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m68k_memory_map[0x60].write16 = NULL;
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break;
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}
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}
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#ifdef LSB_FIRST
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/* Byteswap ROM */
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int i;
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uint8 temp;
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for(i = 0; i < 0x20000; i += 2)
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{
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temp = action_replay.rom[i];
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action_replay.rom[i] = action_replay.rom[i+1];
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action_replay.rom[i+1] = temp;
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}
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#endif
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}
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void datel_reset(int hard_reset)
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{
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if (action_replay.enabled)
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{
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if (hard_reset)
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{
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/* clear RAM */
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memset(action_replay.ram,0,sizeof(action_replay.ram));
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}
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/* reset codes */
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datel_switch(0);
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/* reset internal state */
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memset(action_replay.regs,0,sizeof(action_replay.regs));
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memset(action_replay.old,0,sizeof(action_replay.old));
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memset(action_replay.data,0,sizeof(action_replay.data));
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memset(action_replay.addr,0,sizeof(action_replay.addr));
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/* ROM mapped at $000000-$3fffff */
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switch (action_replay.enabled)
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{
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case TYPE_AR: /* 32k ROM */
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case TYPE_PRO2: /* 64k ROM */
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{
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m68k_memory_map[0].base = action_replay.rom;
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break;
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}
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case TYPE_PRO1: /* 128k ROM */
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{
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m68k_memory_map[0].base = action_replay.rom;
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m68k_memory_map[1].base = action_replay.rom + 0x10000;
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break;
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}
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}
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}
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}
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void datel_switch(int enable)
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{
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int i;
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if (enable)
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{
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int offset;
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/* store old values */
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for (i=0; i<4; i++)
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{
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if (action_replay.data[i])
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{
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offset = action_replay.addr[i] >> 16;
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if (offset < 0x40) /* cartridge ROM */
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action_replay.old[i] = *(uint16 *)(cart.rom + action_replay.addr[i]);
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else if (offset >= 0xe0) /* Work RAM */
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action_replay.old[i] = *(uint16 *)(work_ram + (action_replay.addr[i]&0xffff));
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}
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}
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/* patch new values */
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for (i=0; i<4; i++)
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{
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if (action_replay.data[i])
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{
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offset = action_replay.addr[i] >> 16;
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if (offset < 0x40) /* cartridge ROM */
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*(uint16 *)(cart.rom + action_replay.addr[i]) = action_replay.data[i];
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else if (offset >= 0xe0) /* Work RAM */
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*(uint16 *)(work_ram + (action_replay.addr[i]&0xffff)) = action_replay.data[i];
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}
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}
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/* set RAM write handlers */
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for (i=0xe0; i<0x100; i++)
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{
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m68k_memory_map[i].write8 = wram_write_byte;
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m68k_memory_map[i].write16 = wram_write_word;
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}
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}
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else
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{
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/* restore original data */
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for (i=0; i<4; i++)
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{
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if (action_replay.data[i])
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{
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if (action_replay.addr[i] < 0x400000)
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*(uint16 *)(cart.rom + action_replay.addr[i]) = action_replay.old[i];
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else if (action_replay.addr[i] >= 0xe00000)
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*(uint16 *)(work_ram + (action_replay.addr[i]&0xffff)) = action_replay.old[i];
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}
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}
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/* set default Work RAM write handlers */
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for (i=0xe0; i<0x100; i++)
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{
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m68k_memory_map[i].write8 = NULL;
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m68k_memory_map[i].write16 = NULL;
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}
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}
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}
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static void wram_write_byte(uint32 address, uint32 data)
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{
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int i;
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for (i=0; i<4; i++)
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{
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if ((address & 0xe0fffe) == (action_replay.addr[i]&0xe0fffe))
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{
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if (address & 1) /* lower byte write */
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action_replay.old[i] = (action_replay.old[i] & 0xff00) | (data & 0xff);
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else /* upper byte write */
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action_replay.old[i] = (action_replay.old[i] & 0x00ff) | (data << 8);
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return;
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}
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}
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WRITE_BYTE(work_ram, address & 0xffff, data);
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}
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static void wram_write_word(uint32 address, uint32 data)
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{
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int i;
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for (i=0; i<4; i++)
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{
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if ((address & 0xe0fffe) == (action_replay.addr[i]&0xe0fffe))
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{
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action_replay.old[i] = data;
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return;
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}
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}
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*(uint16 *)(work_ram + (address & 0xffff)) = data;
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}
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static void ar_write_regs(uint32 address, uint32 data)
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{
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if ((address > 0x10018) || (action_replay.regs[3] == 0xffff))
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{
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m68k_unused_16_w(address,data);
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return;
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}
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/* register offset */
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int offset = (address >> 1) & 0x0F;
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/* update internal register */
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action_replay.regs[offset] = data;
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/* decode patch value & address on exit */
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if ((offset == 3) && (data == 0xffff))
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{
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/* decode patch data */
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action_replay.data[0] = action_replay.regs[0];
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action_replay.data[1] = action_replay.regs[4];
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action_replay.data[2] = action_replay.regs[7];
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action_replay.data[3] = action_replay.regs[10];
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/* decode patch address */
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action_replay.addr[0] = (action_replay.regs[1] | ((action_replay.regs[2] & 0x7f00) << 8)) << 1;
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action_replay.addr[1] = (action_replay.regs[5] | ((action_replay.regs[6] & 0x7f00) << 8)) << 1;
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action_replay.addr[2] = (action_replay.regs[8] | ((action_replay.regs[9] & 0x7f00) << 8)) << 1;
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action_replay.addr[3] = (action_replay.regs[11] | ((action_replay.regs[12] & 0x7f00) << 8)) << 1;
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/* Enable Cartridge ROM */
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/* NOTE: codes should be disabled on startup */
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m68k_memory_map[0].base = cart.rom;
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m68k_memory_map[1].base = cart.rom + ((1<<16) & cart.mask);
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}
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}
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static void ar_write_regs_pro2(uint32 address, uint32 data)
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{
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/* Enable Cartridge ROM */
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if (((address & 0xff) == 0x78) && (data == 0xffff))
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m68k_memory_map[0].base = cart.rom;
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}
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