Genesis-Plus-GX/source/cd_hw/cd_cart.c

259 lines
7.9 KiB
C
Raw Normal View History

[Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup. [Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup.
2012-07-05 21:22:12 +02:00
/***************************************************************************************
* Genesis Plus
* CD cartridge (external RAM or ROM)
*
* Copyright (C) 2012 Eke-Eke (Genesis Plus GX)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:
*
* - Redistributions may not be sold, nor may they be used in a commercial
* product or activity.
*
* - Redistributions that are modified from the original source must include the
* complete source code, including the source code for all components used by a
* binary built from the modified sources. However, as a special exception, the
* source code distributed need not include anything that is normally distributed
* (in either source or binary form) with the major components (compiler, kernel,
* and so on) of the operating system on which the executable runs, unless that
* component itself accompanies the executable.
*
* - Redistributions must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************************/
#include "shared.h"
/*--------------------------------------------------------------------------*/
/* cartridge backup RAM (max. 512KB) */
/*--------------------------------------------------------------------------*/
static unsigned int cart_ram_read_byte(unsigned int address)
{
/* LSB only */
if (address & 1)
{
return scd.cartridge.area[(address >> 1) & scd.cartridge.mask];
}
return 0xff;
}
static unsigned int cart_ram_read_word(unsigned int address)
{
return (scd.cartridge.area[(address >> 1) & scd.cartridge.mask] | 0xff00);
}
static void cart_ram_write_byte(unsigned int address, unsigned int data)
{
/* LSB only */
if (address & 1)
{
scd.cartridge.area[(address >> 1) & scd.cartridge.mask] = data;
}
}
static void cart_ram_write_word(unsigned int address, unsigned int data)
{
scd.cartridge.area[(address >> 1) & scd.cartridge.mask] = data & 0xff;
}
/*--------------------------------------------------------------------------*/
/* cartridge RAM ID */
/*--------------------------------------------------------------------------*/
static unsigned int cart_id_read_byte(unsigned int address)
{
/* LSB only */
if (address & 1)
{
return scd.cartridge.id;
}
return 0xff;
}
static unsigned int cart_id_read_word(unsigned int address)
{
return (scd.cartridge.id | 0xff00);
}
/*--------------------------------------------------------------------------*/
/* cartridge RAM write protection */
/*--------------------------------------------------------------------------*/
static unsigned int cart_prot_read_byte(unsigned int address)
{
/* LSB only */
if (address & 1)
{
return scd.cartridge.prot;
}
return 0xff;
}
static unsigned int cart_prot_read_word(unsigned int address)
{
return (scd.cartridge.prot | 0xff00);
}
static void cart_prot_write_byte(unsigned int address, unsigned int data)
{
/* LSB only */
if (address & 1)
{
int i;
if (data & 1)
{
/* cartridge is write enabled */
for (i=0x60; i<0x70; i++)
{
m68k.memory_map[i].write8 = cart_ram_write_byte;
m68k.memory_map[i].write16 = cart_ram_write_word;
zbank_memory_map[i].write = cart_ram_write_byte;
}
}
else
{
/* cartridge is write protected */
for (i=0x60; i<0x70; i++)
{
m68k.memory_map[i].write8 = m68k_unused_8_w;
m68k.memory_map[i].write16 = m68k_unused_16_w;
zbank_memory_map[i].write = zbank_unused_w;
}
}
scd.cartridge.prot = data;
}
}
static void cart_prot_write_word(unsigned int address, unsigned int data)
{
int i;
if (data & 1)
{
/* cartridge is write enabled */
for (i=0x60; i<0x70; i++)
{
m68k.memory_map[i].write8 = cart_ram_write_byte;
m68k.memory_map[i].write16 = cart_ram_write_word;
zbank_memory_map[i].write = cart_ram_write_byte;
}
}
else
{
/* cartridge is write protected */
for (i=0x60; i<0x70; i++)
{
m68k.memory_map[i].write8 = m68k_unused_8_w;
m68k.memory_map[i].write16 = m68k_unused_16_w;
zbank_memory_map[i].write = zbank_unused_w;
}
}
scd.cartridge.prot = data & 0xff;
}
/*--------------------------------------------------------------------------*/
/* cartridge hardware initialization */
/*--------------------------------------------------------------------------*/
void cd_cart_init(void)
{
int i;
/* System boot mode */
if (scd.cartridge.boot)
{
/* disable backup RAM Cart when booting from cartridge (Mode 1) */
scd.cartridge.id = 0;
}
else
{
/* enable 512K backup RAM Cart when booting from CD (Mode 2) */
scd.cartridge.id = 6;
}
/* RAM cart enabled ? */
if (scd.cartridge.id)
{
/* cartridge RAM size mask */
scd.cartridge.mask = (1 << (scd.cartridge.id + 13)) - 1;
/* enable cartridge RAM write access */
scd.cartridge.prot = 1;
/* cartridge ID register (read-only) */
for (i=0x40; i<0x60; i++)
{
m68k.memory_map[i].base = NULL;
m68k.memory_map[i].read8 = cart_id_read_byte;
m68k.memory_map[i].read16 = cart_id_read_word;
m68k.memory_map[i].write8 = m68k_unused_8_w;
m68k.memory_map[i].write16 = m68k_unused_16_w;
zbank_memory_map[i].read = cart_id_read_byte;
zbank_memory_map[i].write = zbank_unused_w;
}
/* cartridge RAM */
for (i=0x60; i<0x70; i++)
{
m68k.memory_map[i].base = NULL;
m68k.memory_map[i].read8 = cart_ram_read_byte;
m68k.memory_map[i].read16 = cart_ram_read_word;
m68k.memory_map[i].write8 = cart_ram_write_byte;
m68k.memory_map[i].write16 = cart_ram_write_word;
zbank_memory_map[i].read = cart_ram_read_byte;
zbank_memory_map[i].write = cart_ram_write_byte;
}
/* cartridge write protection register */
for (i=0x70; i<0x80; i++)
{
m68k.memory_map[i].base = NULL;
m68k.memory_map[i].read8 = cart_prot_read_byte;
m68k.memory_map[i].read16 = cart_prot_read_word;
m68k.memory_map[i].write8 = cart_prot_write_byte;
m68k.memory_map[i].write16 = cart_prot_write_word;
zbank_memory_map[i].read = cart_prot_read_byte;
zbank_memory_map[i].write = cart_prot_write_byte;
}
}
else
{
/* $000000-$3FFFFF (boot from cartridge) or $400000-$7FFFFF (boot from CD) */
uint8 base = scd.cartridge.boot ^ 0x40;
/* cartridge ROM */
for (i=base; i<base+0x40; i++)
{
m68k.memory_map[i].base = scd.cartridge.area + ((i & 0x3f) << 16);
m68k.memory_map[i].read8 = NULL;
m68k.memory_map[i].read16 = NULL;
m68k.memory_map[i].write8 = m68k_unused_8_w;
m68k.memory_map[i].write16 = m68k_unused_16_w;
[Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup. [Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup.
2012-07-05 21:22:12 +02:00
zbank_memory_map[i].read = NULL;
zbank_memory_map[i].write = zbank_unused_w;
[Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup. [Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup.
2012-07-05 21:22:12 +02:00
}
}
}