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[Core/MD] fixed regression with games using SRAM bank-switching (introduced in

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r792)
This commit is contained in:
EkeEke 2013-06-30 13:06:50 +02:00
parent 75ac3317ed
commit 091a0615f5
3 changed files with 84 additions and 59 deletions
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104
core/cart_hw/md_cart.c
View File

@ -4,7 +4,7 @@
*
* Copyright (C) 2007-2013 Eke-Eke (Genesis Plus GX)
*
* Most cartridge protections were initially documented by Haze
* Many cartridge protections were initially documented by Haze
* (http://haze.mameworld.info/)
*
* Realtec mapper was documented by TascoDeluxe
@ -42,6 +42,7 @@
****************************************************************************************/
#include "shared.h"
#include "eeprom_i2c.h"
#include "eeprom_spi.h"
#include "gamepad.h"
@ -356,6 +357,24 @@ void md_cart_init(void)
BACKUP MEMORY
***********************************************/
sram_init();
eeprom_i2c_init();
/* external SRAM */
if (sram.on && !sram.custom)
{
/* disabled on startup if ROM is mapped in same area */
if (cart.romsize <= sram.start)
{
/* initialize m68k bus handlers */
m68k.memory_map[sram.start >> 16].base = sram.sram;
m68k.memory_map[sram.start >> 16].read8 = sram_read_byte;
m68k.memory_map[sram.start >> 16].read16 = sram_read_word;
m68k.memory_map[sram.start >> 16].write8 = sram_write_byte;
m68k.memory_map[sram.start >> 16].write16 = sram_write_word;
zbank_memory_map[sram.start >> 16].read = sram_read_byte;
zbank_memory_map[sram.start >> 16].write = sram_write_byte;
}
}
/**********************************************
SVP CHIP
@ -492,7 +511,7 @@ void md_cart_init(void)
}
/**********************************************
Cartridge Extra Hardware
CARTRIDGE EXTRA HARDWARE
***********************************************/
memset(&cart.hw, 0, sizeof(cart.hw));
@ -607,7 +626,7 @@ void md_cart_init(void)
m68k.memory_map[i].base = cart.rom + ((i & 0x03) << 16);
}
/* 32K SRAM is initially disabled at $200000-$2FFFFF */
/* 32K static RAM is mapped to $200000-$2FFFFF (disabled on startup) */
for (i=0x20; i<0x30; i++)
{
m68k.memory_map[i].base = sram.sram;
@ -789,10 +808,28 @@ int md_cart_context_load(uint8 *state)
if (offset == 0xff)
{
/* SRAM */
m68k.memory_map[i].base = sram.sram;
m68k.memory_map[i].base = sram.sram;
m68k.memory_map[i].read8 = sram_read_byte;
m68k.memory_map[i].read16 = sram_read_word;
m68k.memory_map[i].write8 = sram_write_byte;
m68k.memory_map[i].write16 = sram_write_word;
zbank_memory_map[i].read = sram_read_byte;
zbank_memory_map[i].write = sram_write_byte;
}
else
{
/* check if SRAM was mapped there before loading state */
if (m68k.memory_map[i].base == sram.sram)
{
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;
zbank_memory_map[i].read = NULL;
zbank_memory_map[i].write = zbank_unused_w;
}
/* ROM */
m68k.memory_map[i].base = cart.rom + (offset << 16);
}
@ -829,9 +866,9 @@ static void mapper_sega_w(uint32 data)
{
/* Backup RAM mapped to $200000-$20ffff (normally mirrored up to $3fffff but this breaks Sonic Megamix and no game need it) */
m68k.memory_map[0x20].base = sram.sram;
m68k.memory_map[0x20].write8 = NULL;
m68k.memory_map[0x20].write16 = NULL;
zbank_memory_map[0x20].write = NULL;
m68k.memory_map[0x20].read8 = sram_read_byte;
m68k.memory_map[0x20].read16 = sram_read_word;
zbank_memory_map[0x20].read = sram_read_byte;
/* Backup RAM write protection */
if (data & 2)
@ -840,6 +877,12 @@ static void mapper_sega_w(uint32 data)
m68k.memory_map[0x20].write16 = m68k_unused_16_w;
zbank_memory_map[0x20].write = zbank_unused_w;
}
else
{
m68k.memory_map[0x20].write8 = sram_write_byte;
m68k.memory_map[0x20].write16 = sram_write_word;
zbank_memory_map[0x20].write = sram_write_byte;
}
}
/* S&K lock-on chip */
@ -857,10 +900,13 @@ static void mapper_sega_w(uint32 data)
/* cartridge ROM mapped to $200000-$3fffff */
for (i=0x20; i<0x40; i++)
{
m68k.memory_map[i].base = cart.rom + ((i<<16) & cart.mask);
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;
m68k.memory_map[i].base = cart.rom + ((i<<16) & cart.mask);
m68k.memory_map[i].read8 = NULL;
m68k.memory_map[i].read16 = NULL;
zbank_memory_map[i].read = NULL;
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;
}
}
}
@ -907,10 +953,10 @@ static void mapper_sf001_w(uint32 address, uint32 data)
m68k.memory_map[i].base = cart.rom + (i << 16);
m68k.memory_map[i].read8 = m68k_read_bus_8;
m68k.memory_map[i].read16 = m68k_read_bus_16;
m68k.memory_map[i].write8 = m68k_unused_8_w;
m68k.memory_map[i].write16 = m68k_unused_16_w;
m68k.memory_map[i].write8 = (i > 0x00) ? m68k_unused_8_w : mapper_sf001_w;
m68k.memory_map[i].write16 = (i > 0x00) ? m68k_unused_16_w : mapper_sf001_w;
zbank_memory_map[i].read = zbank_unused_r;
zbank_memory_map[i].write = m68k_unused_8_w;
zbank_memory_map[i].write = (i > 0x00) ? m68k_unused_8_w : mapper_sf001_w;
}
}
@ -939,12 +985,12 @@ static void mapper_sf001_w(uint32 address, uint32 data)
while (i<0x40)
{
m68k.memory_map[i].base = sram.sram;
m68k.memory_map[i].read8 = NULL;
m68k.memory_map[i].read16 = NULL;
m68k.memory_map[i].write8 = NULL;
m68k.memory_map[i].write16 = NULL;
zbank_memory_map[i].read = NULL;
zbank_memory_map[i].write = NULL;
m68k.memory_map[i].read8 = sram_read_byte;
m68k.memory_map[i].read16 = sram_read_word;
m68k.memory_map[i].write8 = sram_write_byte;
m68k.memory_map[i].write16 = sram_write_word;
zbank_memory_map[i].read = sram_read_byte;
zbank_memory_map[i].write = sram_write_byte;
i++;
}
}
@ -956,10 +1002,10 @@ static void mapper_sf001_w(uint32 address, uint32 data)
m68k.memory_map[i].base = cart.rom + (i << 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;
m68k.memory_map[i].write8 = (i > 0x00) ? m68k_unused_8_w : mapper_sf001_w;
m68k.memory_map[i].write16 = (i > 0x00) ? m68k_unused_16_w : mapper_sf001_w;
zbank_memory_map[i].read = NULL;
zbank_memory_map[i].write = m68k_unused_8_w;
zbank_memory_map[i].write = (i > 0x00) ? m68k_unused_8_w : mapper_sf001_w;
}
}
@ -1023,12 +1069,12 @@ static void mapper_sf004_w(uint32 address, uint32 data)
/* 32KB static RAM mirrored into $200000-$2FFFFF (odd bytes only) */
for (i=0x20; i<0x30; i++)
{
m68k.memory_map[i].read8 = NULL;
m68k.memory_map[i].read16 = NULL;
m68k.memory_map[i].write8 = NULL;
m68k.memory_map[i].write16 = NULL;
zbank_memory_map[i].read = NULL;
zbank_memory_map[i].write = NULL;
m68k.memory_map[i].read8 = sram_read_byte;
m68k.memory_map[i].read16 = sram_read_word;
m68k.memory_map[i].write8 = sram_write_byte;
m68k.memory_map[i].write16 = sram_write_word;
zbank_memory_map[i].read = sram_read_byte;
zbank_memory_map[i].write = sram_write_byte;
}
}
else

33
core/cart_hw/sram.c
View File

@ -37,15 +37,9 @@
****************************************************************************************/
#include "shared.h"
#include "eeprom_i2c.h"
T_SRAM sram;
static unsigned int sram_read_byte(unsigned int address);
static unsigned int sram_read_word(unsigned int address);
static void sram_write_byte(unsigned int address, unsigned int data);
static void sram_write_word(unsigned int address, unsigned int data);
/****************************************************************************
* A quick guide to external RAM on the Genesis
*
@ -194,44 +188,25 @@ void sram_init()
sram.on = 1;
}
}
/* autodetect games with serial EEPROM */
eeprom_i2c_init();
/* initialize m68k bus handlers (if not already done) */
if (sram.on && !sram.custom)
{
/* disabled on startup if ROM is mapped in same area */
if (cart.romsize <= sram.start)
{
m68k.memory_map[sram.start >> 16].base = sram.sram;
m68k.memory_map[sram.start >> 16].read8 = sram_read_byte;
m68k.memory_map[sram.start >> 16].read16 = sram_read_word;
m68k.memory_map[sram.start >> 16].write8 = sram_write_byte;
m68k.memory_map[sram.start >> 16].write16 = sram_write_word;
zbank_memory_map[sram.start >> 16].read = sram_read_byte;
zbank_memory_map[sram.start >> 16].write = sram_write_byte;
}
}
}
static unsigned int sram_read_byte(unsigned int address)
unsigned int sram_read_byte(unsigned int address)
{
return sram.sram[address & 0xffff];
}
static unsigned int sram_read_word(unsigned int address)
unsigned int sram_read_word(unsigned int address)
{
address &= 0xfffe;
return (sram.sram[address + 1] | (sram.sram[address] << 8));
}
static void sram_write_byte(unsigned int address, unsigned int data)
void sram_write_byte(unsigned int address, unsigned int data)
{
sram.sram[address & 0xffff] = data;
}
static void sram_write_word(unsigned int address, unsigned int data)
void sram_write_word(unsigned int address, unsigned int data)
{
address &= 0xfffe;
sram.sram[address] = data >> 8;

4
core/cart_hw/sram.h
View File

@ -52,6 +52,10 @@ typedef struct
/* Function prototypes */
extern void sram_init();
extern unsigned int sram_read_byte(unsigned int address);
extern unsigned int sram_read_word(unsigned int address);
extern void sram_write_byte(unsigned int address, unsigned int data);
extern void sram_write_word(unsigned int address, unsigned int data);
/* global variables */
extern T_SRAM sram;