[Core/MD] added (very basic) emulation of Flashkit MD hardware

HISTORY.txt

@@ -43,6 +43,7 @@ Genesis Plus GX 1.7.5 (xx/xx/xxxx) (Eke-Eke)
 ---------------
 * added support for some new unlicensed games with copy protection (Thunderbolt II, Tom Clown, Chaoji Puke / Super Poker)
 * added support for Everdrive extended SSF mapper
+* added (very basic) emulation of Flashkit MD hardware
 * improved console region auto-detection for a few PAL-only games (The Smurfs Travel the World & Williams Arcade's Greatest Hits)
 * improved I2C EEPROM boards emulation accuracy
 * improved SVP memory handlers accuracy (fixes Virtua Racing debug mode)

core/cart_hw/md_cart.c

@@ -2,7 +2,7 @@
  *  Genesis Plus
  *  Mega Drive cartridge hardware support
  *
- *  Copyright (C) 2007-2016  Eke-Eke (Genesis Plus GX)
+ *  Copyright (C) 2007-2017  Eke-Eke (Genesis Plus GX)
  *
  *  Many cartridge protections were initially documented by Haze
  *  (http://haze.mameworld.info/)
@@ -65,6 +65,8 @@ static void mapper_sf004_w(uint32 address, uint32 data);
 static uint32 mapper_sf004_r(uint32 address);
 static void mapper_t5740_w(uint32 address, uint32 data);
 static uint32 mapper_t5740_r(uint32 address);
+static void mapper_flashkit_w(uint32 address, uint32 data);
+static uint32 mapper_flashkit_r(uint32 address);
 static uint32 mapper_smw_64_r(uint32 address);
 static void mapper_smw_64_w(uint32 address, uint32 data);
 static void mapper_realtec_w(uint32 address, uint32 data);
@@ -628,6 +630,13 @@ void md_cart_init(void)
       zbank_memory_map[i].write  = zbank_unused_w;
     }
   }
+  else if (strstr(rominfo.ROMType,"GM") && strstr(rominfo.product,"00000000-42"))
+  {
+    /* Flashkit MD mapper */
+    m68k.memory_map[0x00].write8 = mapper_flashkit_w;
+    m68k.memory_map[0x00].write16 = mapper_flashkit_w;
+    zbank_memory_map[0x00].write = mapper_flashkit_w;
+  }
   else if ((*(uint16 *)(cart.rom + 0x08) == 0x6000) && (*(uint16 *)(cart.rom + 0x0a) == 0x01f6) && (rominfo.realchecksum == 0xf894))
   {
     /* Super Mario World 64 (unlicensed) mapper */
@@ -1267,6 +1276,44 @@ static uint32 mapper_t5740_r(uint32 address)
   return READ_BYTE(cart.rom, address);
 }
 
+/* 
+  FlashKit MD mapper (very limited M29W320xx Flash memory support -- enough for unlicensed games using device signature as protection) 
+*/
+static void mapper_flashkit_w(uint32 address, uint32 data)
+{
+  /* Increment Bus Write counter */
+  cart.hw.regs[0]++;
+
+  /* Wait for 3 consecutive bus writes */
+  if (cart.hw.regs[0] == 3)
+  {
+    /* assume 'Auto Select' command */
+    m68k.memory_map[0x0].read16 = mapper_flashkit_r;
+  }
+  else if (cart.hw.regs[0] == 4)
+  {
+    /* assume 'Read/Reset' command */
+    m68k.memory_map[0x0].read16 = NULL;
+
+    /* reset Bus Write counter */
+    cart.hw.regs[0] = 0;
+  }
+}
+
+static uint32 mapper_flashkit_r(uint32 address)
+{
+  /* hard-coded device signature */
+  switch (address & 0x06)
+  {
+    case 0x00:  /* Manufacturer Code (STMicroelectronics) */
+      return 0x0020;
+    case 0x02:  /* Device Code (M29W320EB) */
+      return 0x2257;
+    default:    /* not supported */
+      return 0xffff;
+  }
+}
+
 /* 
   Super Mario World 64 (unlicensed) mapper
 */

core/cart_hw/md_cart.h

@@ -2,7 +2,7 @@
  *  Genesis Plus
  *  Mega Drive cartridge hardware support
  *
- *  Copyright (C) 2007-2016  Eke-Eke (Genesis Plus GX)
+ *  Copyright (C) 2007-2017  Eke-Eke (Genesis Plus GX)
  *
  *  Most cartridge protections were initially documented by Haze
  *  (http://haze.mameworld.info/)