From 7033010412c36bc4d99a92dcf6d91a5c19a8bd1f Mon Sep 17 00:00:00 2001
From: EkeEke <ekeeke31@gmail.com>
Date: Tue, 9 Jul 2013 00:36:44 +0200
Subject: [PATCH] [Core/MD] disable cartridge backup RAM when mapped as
 volatile RAM over internal RAM ("Feng Kuang Tao Hua Yuan" crash)

---
 core/cart_hw/sram.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/core/cart_hw/sram.c b/core/cart_hw/sram.c
index 382cf13..ed8bea9 100644
--- a/core/cart_hw/sram.c
+++ b/core/cart_hw/sram.c
@@ -77,6 +77,9 @@ void sram_init()
     /* backup RAM detected */
     sram.detected = 1;
 
+    /* enable backup RAM */
+    sram.on = 1;
+
     /* retrieve backup RAM start & end addresses */
     sram.start = READ_WORD_LONG(cart.rom, 0x1b4);
     sram.end   = READ_WORD_LONG(cart.rom, 0x1b8);
@@ -89,14 +92,18 @@ void sram_init()
       sram.end = 0x203fff;
     }
 
+    /* fixe games indicating internal RAM as volatile external RAM (Feng Kuang Tao Hua Yuan) */
+    else if (sram.start == 0xff0000)
+    {
+      /* backup RAM should be disabled */
+      sram.on = 0;
+    }
+
     /* fixe other bad header informations */
     else if ((sram.start > sram.end) || ((sram.end - sram.start) >= 0x10000))
     {
       sram.end = sram.start + 0xffff;
     }
-
-    /* enable backup RAM */
-    sram.on = 1;
   }
   else
   {