From c41976f23ce5b7c9d81ef3c3159b5b3cc37859d2 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Sun, 23 Mar 2014 10:09:53 -0600
Subject: [PATCH] Clean-up AVR stack colorization logic

---
 arch/avr/Kconfig                    | 1 +
 arch/avr/src/avr/up_createstack.c   | 2 +-
 arch/avr/src/avr/up_usestack.c      | 2 +-
 arch/avr/src/avr32/up_createstack.c | 2 +-
 arch/avr/src/avr32/up_usestack.c    | 8 ++++++++
 arch/avr/src/common/up_internal.h   | 8 ++++++++
 6 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/arch/avr/Kconfig b/arch/avr/Kconfig
index 7e4b74a54c..917653fdce 100644
--- a/arch/avr/Kconfig
+++ b/arch/avr/Kconfig
@@ -32,6 +32,7 @@ endchoice
 config ARCH_FAMILY_AVR
 	bool
 	default n
+	select ARCH_HAVE_STACKCHECK
 
 config ARCH_FAMILY_AVR32
 	bool
diff --git a/arch/avr/src/avr/up_createstack.c b/arch/avr/src/avr/up_createstack.c
index e82473ef09..5212131261 100644
--- a/arch/avr/src/avr/up_createstack.c
+++ b/arch/avr/src/avr/up_createstack.c
@@ -170,7 +170,7 @@ int up_create_stack(FAR struct tcb_s *tcb, size_t stack_size, uint8_t ttype)
        */
 
 #if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_STACK)
-      memset(tcb->stack_alloc_ptr, 0xaa, stack_size);
+      memset(tcb->stack_alloc_ptr, STACK_COLOR, stack_size);
 #endif
 
       /* The AVR uses a push-down stack:  the stack grows toward lower
diff --git a/arch/avr/src/avr/up_usestack.c b/arch/avr/src/avr/up_usestack.c
index 629ad6cf02..cb19ed241b 100644
--- a/arch/avr/src/avr/up_usestack.c
+++ b/arch/avr/src/avr/up_usestack.c
@@ -112,7 +112,7 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
    */
 
 #if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_STACK)
-   memset(tcb->stack_alloc_ptr, 0xaa, stack_size);
+   memset(tcb->stack_alloc_ptr, STACK_COLOR, stack_size);
 #endif
 
   /* The AVR uses a push-down stack:  the stack grows toward loweraddresses in
diff --git a/arch/avr/src/avr32/up_createstack.c b/arch/avr/src/avr32/up_createstack.c
index f6e1ab635c..f9968d5551 100644
--- a/arch/avr/src/avr32/up_createstack.c
+++ b/arch/avr/src/avr32/up_createstack.c
@@ -170,7 +170,7 @@ int up_create_stack(FAR struct tcb_s *tcb, size_t stack_size, uint8_t ttype)
        */
 
 #if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_STACK)
-      memset(tcb->stack_alloc_ptr, 0xaa, stack_size);
+      memset(tcb->stack_alloc_ptr, STACK_COLOR, stack_size);
 #endif
 
       /* The AVR32 uses a push-down stack:  the stack grows toward lower
diff --git a/arch/avr/src/avr32/up_usestack.c b/arch/avr/src/avr32/up_usestack.c
index e71be16e7e..f606ff3857 100644
--- a/arch/avr/src/avr32/up_usestack.c
+++ b/arch/avr/src/avr32/up_usestack.c
@@ -107,6 +107,14 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
 
   tcb->stack_alloc_ptr = stack;
 
+  /* If stack debug is enabled, then fill the stack with a recognizable value
+   * that we can use later to test for high water marks.
+   */
+
+#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_STACK)
+   memset(tcb->stack_alloc_ptr, STACK_COLOR, stack_size);
+#endif
+
   /* The AVR32 uses a push-down stack:  the stack grows
    * toward loweraddresses in memory.  The stack pointer
    * register, points to the lowest, valid work address
diff --git a/arch/avr/src/common/up_internal.h b/arch/avr/src/common/up_internal.h
index 77d75afeb8..75c9e5cb17 100644
--- a/arch/avr/src/common/up_internal.h
+++ b/arch/avr/src/common/up_internal.h
@@ -73,6 +73,14 @@
 # define CONFIG_ARCH_INTERRUPTSTACK 0
 #endif
 
+/* This is the value used to mark the stack for subsequent stack monitoring
+ * logic.
+ */
+
+#define STACK_COLOR    's'
+#define INTSTACK_COLOR 's'
+#define HEAP_COLOR     'h'
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/