diff --git a/bsp/mini2440/mini2440_ram.ld b/bsp/mini2440/mini2440_ram.ld
index 9eb287ffd..37c06324e 100644
--- a/bsp/mini2440/mini2440_ram.ld
+++ b/bsp/mini2440/mini2440_ram.ld
@@ -62,9 +62,6 @@ SECTIONS
 	.nobss : { *(.nobss) }
 
 	. = 0x30200000;
-	.mmu_table : { *(.mmu_table) }
-
-	. = 0x30300000;
 	. = ALIGN(4);
 	__bss_start = .;
 	.bss : { *(.bss) }
diff --git a/bsp/mini2440/rtthread-mini2440.sct b/bsp/mini2440/rtthread-mini2440.sct
index 8eda8ada8..5b0c1d734 100644
--- a/bsp/mini2440/rtthread-mini2440.sct
+++ b/bsp/mini2440/rtthread-mini2440.sct
@@ -5,14 +5,14 @@ LR_IROM1 0x30000000 0x1000000 {
    .ANY (+RO)
   }
 
-  ER_MMU 0x30400000 EMPTY 0x00100000 {
-  }
-
-  RW_IRAM1 0x30500000 {  ; RW data
+  RW_IRAM1 +0 {  ; RW data
    .ANY (+RW)
   }
 
   ER_ZI +0 { ; ZI data
    .ANY (+ZI)
   }
+
+  ER_MMU 0x33FF0000 EMPTY 0x00100000 {
+  }
 }
diff --git a/bsp/mini2440/startup.c b/bsp/mini2440/startup.c
index 0fd8d2bda..29f07a765 100644
--- a/bsp/mini2440/startup.c
+++ b/bsp/mini2440/startup.c
@@ -54,7 +54,8 @@ extern struct rt_device uart0_device;
 	rt_uint8_t _undefined_stack_start[512];
 	rt_uint8_t _abort_stack_start[512];
 	rt_uint8_t _svc_stack_start[1024] SECTION(".nobss");
-	extern int __bss_end;
+	extern unsigned char __bss_start;
+	extern unsigned char __bss_end;
 #endif
 
 /**
@@ -63,7 +64,6 @@ extern struct rt_device uart0_device;
  #if (defined (__GNUC__))
 void *_sbrk (int incr)
 { 
-	extern int   __bss_end; /* Set by linker.  */
 	static char * heap_end; 
 	char *        prev_heap_end; 
 
@@ -110,9 +110,9 @@ void rtthread_startup(void)
 
 	/* init heap memory system */
 #ifdef __CC_ARM
-	rt_system_heap_init((void*)&Image$$ER_ZI$$ZI$$Limit, (void*)0x34000000);
+	rt_system_heap_init((void*)&Image$$ER_ZI$$ZI$$Limit, (void*)0x33F00000);
 #else
-	rt_system_heap_init((void*)0x32000000, (void*)0x34000000);
+	rt_system_heap_init((void*)&__bss_end, (void*)0x33F00000);
 #endif
 
 	/* init scheduler system */