diff --git a/libcpu/arm/AT91SAM7S/stack.c b/libcpu/arm/AT91SAM7S/stack.c
index b0dc78db2..14acc5445 100644
--- a/libcpu/arm/AT91SAM7S/stack.c
+++ b/libcpu/arm/AT91SAM7S/stack.c
@@ -30,31 +30,34 @@
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	unsigned long *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (unsigned long *)stack_addr;
-	*(stk) 	 = (unsigned long)tentry;		/* entry point */
-	*(--stk) = (unsigned long)texit;		/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (unsigned long)parameter;	/* r0 : argument */
-	*(--stk) = SVCMODE;						/* cpsr */
-	*(--stk) = SVCMODE;						/* spsr */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
+    *(--stk) = SVCMODE;                     /* cpsr */
+    *(--stk) = SVCMODE;                     /* spsr */
+
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/AT91SAM7X/stack.c b/libcpu/arm/AT91SAM7X/stack.c
index 6060b6372..d6711a529 100644
--- a/libcpu/arm/AT91SAM7X/stack.c
+++ b/libcpu/arm/AT91SAM7X/stack.c
@@ -13,7 +13,7 @@
  */
 #include <rtthread.h>
 
-#define SVCMODE				0x13
+#define SVCMODE             0x13
 
 /**
  * @addtogroup AT91SAM7
@@ -31,31 +31,33 @@
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	unsigned long *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (unsigned long *)stack_addr;
-	*(stk) 	 = (unsigned long)tentry;		/* entry point */
-	*(--stk) = (unsigned long)texit;		/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (unsigned long)parameter;	/* r0 : argument */
-	*(--stk) = SVCMODE;						/* cpsr */
-	*(--stk) = SVCMODE;						/* spsr */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
+    *(--stk) = SVCMODE;                     /* cpsr */
+    *(--stk) = SVCMODE;                     /* spsr */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/am335x/stack.c b/libcpu/arm/am335x/stack.c
index e46f34f7c..7415e230f 100644
--- a/libcpu/arm/am335x/stack.c
+++ b/libcpu/arm/am335x/stack.c
@@ -24,42 +24,45 @@
  * This function will initialize thread stack
  *
  * @param tentry the entry of thread
- * @param parameter the parameter of entry 
+ * @param parameter the parameter of entry
  * @param stack_addr the beginning stack address
  * @param texit the function will be called when thread exit
  *
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	rt_uint32_t *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (rt_uint32_t*)stack_addr;
-	*(stk) 	 = (rt_uint32_t)tentry;			/* entry point */
-	*(--stk) = (rt_uint32_t)texit;			/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (rt_uint32_t)parameter;		/* r0 : argument */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
 
-	/* cpsr */
-	if ((rt_uint32_t)tentry & 0x01)
-		*(--stk) = SVCMODE | 0x20;			/* thumb mode */
-	else
-		*(--stk) = SVCMODE;					/* arm mode   */
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* cpsr */
+    if ((rt_uint32_t)tentry & 0x01)
+        *(--stk) = SVCMODE | 0x20;          /* thumb mode */
+    else
+        *(--stk) = SVCMODE;                 /* arm mode   */
+
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/arm926/stack.c b/libcpu/arm/arm926/stack.c
index ee29aad3a..966088f82 100644
--- a/libcpu/arm/arm926/stack.c
+++ b/libcpu/arm/arm926/stack.c
@@ -50,10 +50,9 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
 {
     rt_uint32_t *stk;
 
-    //stk      = (rt_uint32_t*)stack_addr;
     stack_addr += sizeof(rt_uint32_t);
     stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
-    stk  = (rt_uint32_t *)stack_addr;
+    stk      = (rt_uint32_t *)stack_addr;
 
     *(--stk) = (rt_uint32_t)tentry;         /* entry point */
     *(--stk) = (rt_uint32_t)texit;          /* lr */
@@ -70,11 +69,11 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
     *(--stk) = 0xdeadbeef;                  /* r2 */
     *(--stk) = 0xdeadbeef;                  /* r1 */
     *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
-	/* cpsr */
-	if ((rt_uint32_t)tentry & 0x01)
-		*(--stk) = SVCMODE | 0x20;			/* thumb mode */
-	else
-		*(--stk) = SVCMODE;					/* arm mode   */
+    /* cpsr */
+    if ((rt_uint32_t)tentry & 0x01)
+        *(--stk) = SVCMODE | 0x20;          /* thumb mode */
+    else
+        *(--stk) = SVCMODE;                 /* arm mode   */
 
     /* return task's current stack address */
     return (rt_uint8_t *)stk;
diff --git a/libcpu/arm/cortex-a/stack.c b/libcpu/arm/cortex-a/stack.c
index e653c5d11..e60e8c717 100644
--- a/libcpu/arm/cortex-a/stack.c
+++ b/libcpu/arm/cortex-a/stack.c
@@ -32,35 +32,37 @@
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	rt_uint32_t *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (rt_uint32_t*)stack_addr;
-	*(stk) 	 = (rt_uint32_t)tentry;			/* entry point */
-	*(--stk) = (rt_uint32_t)texit;			/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (rt_uint32_t)parameter;		/* r0 : argument */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
 
-	/* cpsr */
-	if ((rt_uint32_t)tentry & 0x01)
-		*(--stk) = SVCMODE | 0x20;			/* thumb mode */
-	else
-		*(--stk) = SVCMODE;					/* arm mode   */
+    /* cpsr */
+    if ((rt_uint32_t)tentry & 0x01)
+        *(--stk) = SVCMODE | 0x20;          /* thumb mode */
+    else
+        *(--stk) = SVCMODE;                 /* arm mode   */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/cortex-r4/stack.c b/libcpu/arm/cortex-r4/stack.c
index 3c8e89444..852c6ea38 100644
--- a/libcpu/arm/cortex-r4/stack.c
+++ b/libcpu/arm/cortex-r4/stack.c
@@ -24,39 +24,41 @@
  * This function will initialize thread stack
  *
  * @param tentry the entry of thread
- * @param parameter the parameter of entry 
+ * @param parameter the parameter of entry
  * @param stack_addr the beginning stack address
  * @param texit the function will be called when thread exit
  *
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	unsigned long *stk;
+    rt_uint32_t *stk;
 
-	    stk  = (unsigned long*)stack_addr;
-	*(  stk) = (unsigned long) tentry;		/* entry point */
-	*(--stk) = (unsigned long) texit;		/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (unsigned long)parameter;	/* r0 : argument */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
 
-	/* cpsr */
-	if ((rt_uint32_t)tentry & 0x01)
-		*(--stk) = SVCMODE | 0x20;			/* thumb mode */
-	else
-		*(--stk) = SVCMODE;					/* arm mode   */
+    /* cpsr */
+    if ((rt_uint32_t)tentry & 0x01)
+        *(--stk) = SVCMODE | 0x20;          /* thumb mode */
+    else
+        *(--stk) = SVCMODE;                 /* arm mode   */
 
 #if defined(__TI_VFP_SUPPORT__) || (defined (__VFP_FP__) && !defined(__SOFTFP__))
 #ifndef RT_VFP_LAZY_STACKING
@@ -73,13 +75,13 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
         *(--stk) = 0x40000000;
     }
 #else
-        /* FPEXC. Disable the FVP by default. */
-        *(--stk) = 0x00000000;
+    /* FPEXC. Disable the FVP by default. */
+    *(--stk) = 0x00000000;
 #endif
 #endif
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/dm36x/stack.c b/libcpu/arm/dm36x/stack.c
index b41b0b859..fd56e7a49 100644
--- a/libcpu/arm/dm36x/stack.c
+++ b/libcpu/arm/dm36x/stack.c
@@ -26,54 +26,56 @@
 /*****************************/
 /* CPU Mode                  */
 /*****************************/
-#define USERMODE		0x10
-#define FIQMODE			0x11
-#define IRQMODE			0x12
-#define SVCMODE			0x13
-#define ABORTMODE		0x17
-#define UNDEFMODE		0x1b
-#define MODEMASK		0x1f
-#define NOINT			0xc0
+#define USERMODE        0x10
+#define FIQMODE         0x11
+#define IRQMODE         0x12
+#define SVCMODE         0x13
+#define ABORTMODE       0x17
+#define UNDEFMODE       0x1b
+#define MODEMASK        0x1f
+#define NOINT           0xc0
 
 /**
  * This function will initialize thread stack
  *
  * @param tentry the entry of thread
- * @param parameter the parameter of entry 
+ * @param parameter the parameter of entry
  * @param stack_addr the beginning stack address
  * @param texit the function will be called when thread exit
  *
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	rt_uint32_t *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (rt_uint32_t*)stack_addr;
-	*(stk) 	 = (rt_uint32_t)tentry;			/* entry point */
-	*(--stk) = (rt_uint32_t)texit;			/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (rt_uint32_t)parameter;		/* r0 : argument */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
 
-	/* cpsr */
-	if ((rt_uint32_t)tentry & 0x01)
-		*(--stk) = SVCMODE | 0x20;			/* thumb mode */
-	else
-		*(--stk) = SVCMODE;					/* arm mode   */
+    /* cpsr */
+    if ((rt_uint32_t)tentry & 0x01)
+        *(--stk) = SVCMODE | 0x20;          /* thumb mode */
+    else
+        *(--stk) = SVCMODE;                 /* arm mode   */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
diff --git a/libcpu/arm/lpc24xx/stack.c b/libcpu/arm/lpc24xx/stack.c
index ad6419da4..f160e9c16 100644
--- a/libcpu/arm/lpc24xx/stack.c
+++ b/libcpu/arm/lpc24xx/stack.c
@@ -23,42 +23,45 @@
  * This function will initialize thread stack
  *
  * @param tentry the entry of thread
- * @param parameter the parameter of entry 
+ * @param parameter the parameter of entry
  * @param stack_addr the beginning stack address
  * @param texit the function will be called when thread exit
  *
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	unsigned long *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (unsigned long *)stack_addr;
-	*(stk) 	 = (unsigned long)tentry;		/* entry point */
-	*(--stk) = (unsigned long)texit;		/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (unsigned long)parameter;	/* r0 : argument */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
 
-	/* cpsr */
-	if ((rt_uint32_t)tentry & 0x01)
-		*(--stk) = SVCMODE | 0x20;			/* thumb mode */
-	else
-		*(--stk) = SVCMODE;					/* arm mode   */
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* cpsr */
+    if ((rt_uint32_t)tentry & 0x01)
+        *(--stk) = SVCMODE | 0x20;          /* thumb mode */
+    else
+        *(--stk) = SVCMODE;                 /* arm mode   */
+
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/realview-a8-vmm/stack.c b/libcpu/arm/realview-a8-vmm/stack.c
index 4ae1536a2..94080ae74 100644
--- a/libcpu/arm/realview-a8-vmm/stack.c
+++ b/libcpu/arm/realview-a8-vmm/stack.c
@@ -24,42 +24,44 @@
  * This function will initialize thread stack
  *
  * @param tentry the entry of thread
- * @param parameter the parameter of entry 
+ * @param parameter the parameter of entry
  * @param stack_addr the beginning stack address
  * @param texit the function will be called when thread exit
  *
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	rt_uint32_t *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (rt_uint32_t*)stack_addr;
-	*(stk) 	 = (rt_uint32_t)tentry;			/* entry point */
-	*(--stk) = (rt_uint32_t)texit;			/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (rt_uint32_t)parameter;		/* r0 : argument */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
 
-	/* cpsr */
-	if ((rt_uint32_t)tentry & 0x01)
-		*(--stk) = SVCMODE | 0x20;			/* thumb mode */
-	else
-		*(--stk) = SVCMODE;					/* arm mode   */
+    /* cpsr */
+    if ((rt_uint32_t)tentry & 0x01)
+        *(--stk) = SVCMODE | 0x20;          /* thumb mode */
+    else
+        *(--stk) = SVCMODE;                 /* arm mode   */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/s3c24x0/stack.c b/libcpu/arm/s3c24x0/stack.c
index a284989fe..315091d90 100644
--- a/libcpu/arm/s3c24x0/stack.c
+++ b/libcpu/arm/s3c24x0/stack.c
@@ -23,38 +23,41 @@
  * This function will initialize thread stack
  *
  * @param tentry the entry of thread
- * @param parameter the parameter of entry 
+ * @param parameter the parameter of entry
  * @param stack_addr the beginning stack address
  * @param texit the function will be called when thread exit
  *
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	rt_uint32_t *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (rt_uint32_t*)stack_addr;
-	*(stk) 	 = (rt_uint32_t)tentry;			/* entry point */
-	*(--stk) = (rt_uint32_t)texit;			/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (rt_uint32_t)parameter;		/* r0 : argument */
-	*(--stk) = SVCMODE;						/* cpsr */
-	*(--stk) = SVCMODE;						/* spsr */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
+    *(--stk) = SVCMODE;                     /* cpsr */
+    *(--stk) = SVCMODE;                     /* spsr */
+
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/s3c44b0/stack.c b/libcpu/arm/s3c44b0/stack.c
index 3f1d88a39..6f838cb17 100644
--- a/libcpu/arm/s3c44b0/stack.c
+++ b/libcpu/arm/s3c44b0/stack.c
@@ -30,31 +30,33 @@
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	unsigned long *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (unsigned long *)stack_addr;
-	*(stk) 	 = (unsigned long)tentry;		/* entry point */
-	*(--stk) = (unsigned long)texit;		/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (unsigned long)parameter;	/* r0 : argument */
-	*(--stk) = SVCMODE;						/* cpsr */
-	*(--stk) = SVCMODE;						/* spsr */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
+    *(--stk) = SVCMODE;                     /* cpsr */
+    *(--stk) = SVCMODE;                     /* spsr */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/sep4020/stack.c b/libcpu/arm/sep4020/stack.c
index 7700373ff..318b435f8 100644
--- a/libcpu/arm/sep4020/stack.c
+++ b/libcpu/arm/sep4020/stack.c
@@ -22,38 +22,40 @@
  * This function will initialize thread stack
  *
  * @param tentry the entry of thread
- * @param parameter the parameter of entry 
+ * @param parameter the parameter of entry
  * @param stack_addr the beginning stack address
  * @param texit the function will be called when thread exit
  *
  * @return stack address
  */
 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
-	rt_uint8_t *stack_addr, void *texit)
+                             rt_uint8_t *stack_addr, void *texit)
 {
-	rt_uint32_t *stk;
+    rt_uint32_t *stk;
 
-	stk 	 = (rt_uint32_t*)stack_addr;
-	*(stk) 	 = (rt_uint32_t)tentry;			/* entry point */
-	*(--stk) = (rt_uint32_t)texit;			/* lr */
-	*(--stk) = 0;							/* r12 */
-	*(--stk) = 0;							/* r11 */
-	*(--stk) = 0;							/* r10 */
-	*(--stk) = 0;							/* r9 */
-	*(--stk) = 0;							/* r8 */
-	*(--stk) = 0;							/* r7 */
-	*(--stk) = 0;							/* r6 */
-	*(--stk) = 0;							/* r5 */
-	*(--stk) = 0;							/* r4 */
-	*(--stk) = 0;							/* r3 */
-	*(--stk) = 0;							/* r2 */
-	*(--stk) = 0;							/* r1 */
-	*(--stk) = (rt_uint32_t)parameter;		/* r0 : argument */
-	*(--stk) = Mode_SVC;					/* cpsr */
-	*(--stk) = Mode_SVC;					/* spsr */
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
+    stk      = (rt_uint32_t *)stack_addr;
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)texit;          /* lr */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
+    *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
+    *(--stk) = Mode_SVC;                    /* cpsr */
+    *(--stk) = Mode_SVC;                    /* spsr */
 
-	/* return task's current stack address */
-	return (rt_uint8_t *)stk;
+    /* return task's current stack address */
+    return (rt_uint8_t *)stk;
 }
 
 /*@}*/
diff --git a/libcpu/arm/zynq7000/stack.c b/libcpu/arm/zynq7000/stack.c
index 8e1b86432..08dd4b4da 100644
--- a/libcpu/arm/zynq7000/stack.c
+++ b/libcpu/arm/zynq7000/stack.c
@@ -31,21 +31,23 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
 {
     rt_uint32_t *stk;
 
+    stack_addr += sizeof(rt_uint32_t);
+    stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
     stk      = (rt_uint32_t *)stack_addr;
-    *(stk)   = (rt_uint32_t)tentry;         /* entry point */
+    *(--stk) = (rt_uint32_t)tentry;         /* entry point */
     *(--stk) = (rt_uint32_t)texit;          /* lr */
-    *(--stk) = 0;                           /* r12 */
-    *(--stk) = 0;                           /* r11 */
-    *(--stk) = 0;                           /* r10 */
-    *(--stk) = 0;                           /* r9 */
-    *(--stk) = 0;                           /* r8 */
-    *(--stk) = 0;                           /* r7 */
-    *(--stk) = 0;                           /* r6 */
-    *(--stk) = 0;                           /* r5 */
-    *(--stk) = 0;                           /* r4 */
-    *(--stk) = 0;                           /* r3 */
-    *(--stk) = 0;                           /* r2 */
-    *(--stk) = 0;                           /* r1 */
+    *(--stk) = 0xdeadbeef;                  /* r12 */
+    *(--stk) = 0xdeadbeef;                  /* r11 */
+    *(--stk) = 0xdeadbeef;                  /* r10 */
+    *(--stk) = 0xdeadbeef;                  /* r9 */
+    *(--stk) = 0xdeadbeef;                  /* r8 */
+    *(--stk) = 0xdeadbeef;                  /* r7 */
+    *(--stk) = 0xdeadbeef;                  /* r6 */
+    *(--stk) = 0xdeadbeef;                  /* r5 */
+    *(--stk) = 0xdeadbeef;                  /* r4 */
+    *(--stk) = 0xdeadbeef;                  /* r3 */
+    *(--stk) = 0xdeadbeef;                  /* r2 */
+    *(--stk) = 0xdeadbeef;                  /* r1 */
     *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
 
     /* cpsr */