diff --git a/arch/xtensa/include/irq.h b/arch/xtensa/include/irq.h
index 3e8dfd46660..49bfc5b1384 100644
--- a/arch/xtensa/include/irq.h
+++ b/arch/xtensa/include/irq.h
@@ -158,9 +158,9 @@ struct xcptcontext
   uint32_t saved_cpsr;
 #endif
 
-  /* Register save area */
+  /* Pointer to the register save area on the stack*/
 
-  uint32_t regs[XCPTCONTEXT_REGS];
+  uint32_t *regs;
 
 #ifdef CONFIG_LIB_SYSCALL
   /* The following array holds the return address and the exc_return value
diff --git a/arch/xtensa/src/common/xtensa.h b/arch/xtensa/src/common/xtensa.h
index cef80d3ae99..01a3ed9e061 100644
--- a/arch/xtensa/src/common/xtensa.h
+++ b/arch/xtensa/src/common/xtensa.h
@@ -1,7 +1,7 @@
 /****************************************************************************
- * arch/xtensa/common/xtensa_internal.h
+ * arch/xtensa/common/xtensa.h
  *
- *   Copyright (C) 2011, 2012, 2015 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,8 +33,8 @@
  *
  ****************************************************************************/
 
-#ifndef __ARCH_XTENSA_SRC_COMMON_XTENSA_INTERNAL_H
-#define __ARCH_XTENSA_SRC_COMMON_XTENSA_INTERNAL_H
+#ifndef __ARCH_XTENSA_SRC_COMMON_XTENSA_H
+#define __ARCH_XTENSA_SRC_COMMON_XTENSA_H
 
 /****************************************************************************
  * Included Files
@@ -104,12 +104,12 @@
 # define CONFIG_ARCH_INTERRUPTSTACK 0
 #endif
 
-/* In the XTENSA model, the state is copied from the stack to the TCB, but
- * only a referenced is passed to get the state from the TCB.
+/* In the XTENSA model, only a pointer to register state on the stack is
+ * saved in the TCB.
  */
 
-#define up_savestate(regs)    up_copystate(regs, (uint32_t*)g_current_regs)
-#define up_restorestate(regs) (g_current_regs = regs)
+#define up_savestate(regs)     do { reg = g_current_regs; } while (0)
+#define up_restorestate(regs)  do { g_current_regs = regs; } while (0)
 
 /****************************************************************************
  * Public Types
@@ -183,7 +183,7 @@ extern uint32_t _bmxdupba_address;  /* BMX register setting */
 
 #ifndef __ASSEMBLY__
 /* Common Functions *********************************************************/
-/* Common functions define in arch/xtensa/src/common.  These may be replaced
+/* Common functions define in arch/mips/src/common.  These may be replaced
  * with chip-specific functions of the same name if needed.  See also
  * functions prototyped in include/nuttx/arch.h.
  */
@@ -213,21 +213,21 @@ void up_dumpstate(void);
 #  define up_dumpstate()
 #endif
 
-/* Common XTENSA32 functions defined in arch/xtensa/src/XTENSA32 */
+/* Common XTENSA functions */
 /* IRQs */
 
 uint32_t *up_doirq(int irq, uint32_t *regs);
 
-/* Software interrupt 0 handler */
+/* Software interrupt handler */
 
-int up_swint0(int irq, FAR void *context);
+int up_swint(int irq, FAR void *context);
 
 /* Signals */
 
 void up_sigdeliver(void);
 
 /* Chip-specific functions **************************************************/
-/* Chip specific functions defined in arch/xtensa/src/<chip> */
+/* Chip specific functions defined in arch/mips/src/<chip> */
 /* IRQs */
 
 void up_irqinitialize(void);
@@ -282,4 +282,4 @@ void up_usbuninitialize(void);
 #endif
 
 #endif /* __ASSEMBLY__ */
-#endif  /* __ARCH_XTENSA_SRC_COMMON_XTENSA_INTERNAL_H */
+#endif  /* __ARCH_XTENSA_SRC_COMMON_XTENSA_H */
diff --git a/arch/xtensa/src/common/xtensa_allocateheap.c b/arch/xtensa/src/common/xtensa_allocateheap.c
index fc2178b5d10..b821eb4e34b 100644
--- a/arch/xtensa/src/common/xtensa_allocateheap.c
+++ b/arch/xtensa/src/common/xtensa_allocateheap.c
@@ -47,7 +47,7 @@
 #include <arch/board/board.h>
 
 #include "up_arch.h"
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Definitions
diff --git a/arch/xtensa/src/common/xtensa_createstack.c b/arch/xtensa/src/common/xtensa_createstack.c
index 08d310e4979..f895f47a503 100644
--- a/arch/xtensa/src/common/xtensa_createstack.c
+++ b/arch/xtensa/src/common/xtensa_createstack.c
@@ -50,7 +50,7 @@
 #include <arch/board/board.h>
 
 #include "up_arch.h"
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Macros
diff --git a/arch/xtensa/src/common/xtensa_etherstub.c b/arch/xtensa/src/common/xtensa_etherstub.c
index e19b26a208a..b41b7bf6d4a 100644
--- a/arch/xtensa/src/common/xtensa_etherstub.c
+++ b/arch/xtensa/src/common/xtensa_etherstub.c
@@ -39,7 +39,7 @@
 
 #include <nuttx/config.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Definitions
diff --git a/arch/xtensa/src/common/xtensa_exit.c b/arch/xtensa/src/common/xtensa_exit.c
index f300c9b89a7..4f451539d2b 100644
--- a/arch/xtensa/src/common/xtensa_exit.c
+++ b/arch/xtensa/src/common/xtensa_exit.c
@@ -52,7 +52,7 @@
 #include "task/task.h"
 #include "sched/sched.h"
 #include "group/group.h"
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Definitions
diff --git a/arch/xtensa/src/common/xtensa_idle.c b/arch/xtensa/src/common/xtensa_idle.c
index e48441d5b4f..672a0fae1c5 100644
--- a/arch/xtensa/src/common/xtensa_idle.c
+++ b/arch/xtensa/src/common/xtensa_idle.c
@@ -41,7 +41,7 @@
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Public Functions
diff --git a/arch/xtensa/src/common/xtensa_initialize.c b/arch/xtensa/src/common/xtensa_initialize.c
index 1fedf991493..46de907db40 100644
--- a/arch/xtensa/src/common/xtensa_initialize.c
+++ b/arch/xtensa/src/common/xtensa_initialize.c
@@ -58,7 +58,7 @@
 #include <arch/board/board.h>
 
 #include "up_arch.h"
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Private Functions
diff --git a/arch/xtensa/src/common/xtensa_interruptcontext.c b/arch/xtensa/src/common/xtensa_interruptcontext.c
index c6d83d05e06..8b6bf802ec1 100644
--- a/arch/xtensa/src/common/xtensa_interruptcontext.c
+++ b/arch/xtensa/src/common/xtensa_interruptcontext.c
@@ -43,7 +43,7 @@
 #include <nuttx/arch.h>
 #include <nuttx/irq.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Private Types
diff --git a/arch/xtensa/src/common/xtensa_lowputs.c b/arch/xtensa/src/common/xtensa_lowputs.c
index 764f8393a63..f1acb1059de 100644
--- a/arch/xtensa/src/common/xtensa_lowputs.c
+++ b/arch/xtensa/src/common/xtensa_lowputs.c
@@ -39,7 +39,7 @@
 
 #include <nuttx/config.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Definitions
diff --git a/arch/xtensa/src/common/xtensa_puts.c b/arch/xtensa/src/common/xtensa_puts.c
index 47675baa8d6..3eaa3078a4c 100644
--- a/arch/xtensa/src/common/xtensa_puts.c
+++ b/arch/xtensa/src/common/xtensa_puts.c
@@ -40,7 +40,7 @@
 #include <nuttx/config.h>
 #include <nuttx/arch.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Definitions
diff --git a/arch/xtensa/src/common/xtensa_releasestack.c b/arch/xtensa/src/common/xtensa_releasestack.c
index 76b3164bce6..40b5bd75717 100644
--- a/arch/xtensa/src/common/xtensa_releasestack.c
+++ b/arch/xtensa/src/common/xtensa_releasestack.c
@@ -45,7 +45,7 @@
 #include <nuttx/arch.h>
 #include <nuttx/kmalloc.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Private Types
diff --git a/arch/xtensa/src/common/xtensa_stackframe.c b/arch/xtensa/src/common/xtensa_stackframe.c
index f0a1da976df..6c1adc992bd 100644
--- a/arch/xtensa/src/common/xtensa_stackframe.c
+++ b/arch/xtensa/src/common/xtensa_stackframe.c
@@ -46,7 +46,7 @@
 
 #include <nuttx/arch.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Macros
diff --git a/arch/xtensa/src/common/xtensa_usestack.c b/arch/xtensa/src/common/xtensa_usestack.c
index 9b35e2d0a93..83daf2729cb 100644
--- a/arch/xtensa/src/common/xtensa_usestack.c
+++ b/arch/xtensa/src/common/xtensa_usestack.c
@@ -47,7 +47,7 @@
 #include <nuttx/kmalloc.h>
 #include <nuttx/arch.h>
 
-#include "up_internal.h"
+#include "xtensa.h"
 
 /****************************************************************************
  * Pre-processor Definitions