Add a up_stack_frame() interface to allocate a frame of data on a task's stack.

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5768 42af7a65-404d-4744-a932-0658087f49c3

20 files changed, 1408 insertions, 47 deletions

diff --git a/nuttx/arch/arm/src/common/up_stackframe.c b/nuttx/arch/arm/src/common/up_stackframe.c
new file mode 100644
index 000000000..3720d334a
--- /dev/null
+++ b/nuttx/arch/arm/src/common/up_stackframe.c
@@ -0,0 +1,144 @@
+/****************************************************************************
+ * arch/arm/src/common/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/* ARM requires at least a 4-byte stack alignment.  For use with EABI and
+ * floating point, the stack must be aligned to 8-byte addresses.
+ */
+
+#ifndef CONFIG_STACK_ALIGNMENT
+
+/* The symbol  __ARM_EABI__ is defined by GCC if EABI is being used.  If you
+ * are not using GCC, make sure that CONFIG_STACK_ALIGNMENT is set correctly!
+ */
+
+#  ifdef __ARM_EABI__
+#    define CONFIG_STACK_ALIGNMENT 8
+#  else
+#    define CONFIG_STACK_ALIGNMENT 4
+#  endif
+#endif
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (CONFIG_STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/arm/src/lpc17xx/Make.defs b/nuttx/arch/arm/src/lpc17xx/Make.defs
index 469165387..0fec22d12 100644
--- a/nuttx/arch/arm/src/lpc17xx/Make.defs
+++ b/nuttx/arch/arm/src/lpc17xx/Make.defs
@@ -68,7 +68,7 @@ CMN_ASRCS += up_memcpy.S
 endif
 
 ifeq ($(CONFIG_NUTTX_KERNEL),y)
-CMN_CSRCS += up_mpu.c up_task_start.c up_pthread_start.c
+CMN_CSRCS += up_mpu.c up_task_start.c up_pthread_start.c up_stackframe.c
 ifneq ($(CONFIG_DISABLE_SIGNALS),y)
 CMN_CSRCS += up_signal_handler.c
 endif
diff --git a/nuttx/arch/arm/src/sam3u/Make.defs b/nuttx/arch/arm/src/sam3u/Make.defs
index 16ca22401..4abca3b2c 100644
--- a/nuttx/arch/arm/src/sam3u/Make.defs
+++ b/nuttx/arch/arm/src/sam3u/Make.defs
@@ -60,7 +60,7 @@ CMN_ASRCS += up_memcpy.S
 endif
 
 ifeq ($(CONFIG_NUTTX_KERNEL),y)
-CMN_CSRCS += up_mpu.c up_task_start.c up_pthread_start.c
+CMN_CSRCS += up_mpu.c up_task_start.c up_pthread_start.c up_stackframe.c
 ifneq ($(CONFIG_DISABLE_SIGNALS),y)
 CMN_CSRCS += up_signal_handler.c
 endif
diff --git a/nuttx/arch/arm/src/stm32/stm32_otgfsdev.c b/nuttx/arch/arm/src/stm32/stm32_otgfsdev.c
index 3986106d8..b8033fdd5 100644
--- a/nuttx/arch/arm/src/stm32/stm32_otgfsdev.c
+++ b/nuttx/arch/arm/src/stm32/stm32_otgfsdev.c
@@ -1517,7 +1517,6 @@ static inline void stm32_ep0out_receive(FAR struct stm32_ep_s *privep, int bcnt)
 
   DEBUGASSERT(privep && privep->ep.priv);
   priv = (FAR struct stm32_usbdev_s *)privep->ep.priv;
-  DEBUGASSERT(priv->ep0state == EP0STATE_SETUP_OUT);
 
   ullvdbg("EP0: bcnt=%d\n", bcnt);
   usbtrace(TRACE_READ(EP0), bcnt);
diff --git a/nuttx/arch/avr/src/avr/up_stackframe.c b/nuttx/arch/avr/src/avr/up_stackframe.c
new file mode 100644
index 000000000..39253e2b5
--- /dev/null
+++ b/nuttx/arch/avr/src/avr/up_stackframe.c
@@ -0,0 +1,117 @@
+/****************************************************************************
+ * arch/avr/src/avr/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint8_t));
+}
diff --git a/nuttx/arch/avr/src/avr32/up_stackframe.c b/nuttx/arch/avr/src/avr32/up_stackframe.c
new file mode 100644
index 000000000..08c4cf51e
--- /dev/null
+++ b/nuttx/arch/avr/src/avr32/up_stackframe.c
@@ -0,0 +1,133 @@
+/****************************************************************************
+ * arch/avr/src/avr32/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/* The AVR32 stack must be aligned at word (4 byte) boundaries. If necessary 
+ * frame_size must be rounded up to the next boundary
+ */
+
+#define STACK_ALIGNMENT     4
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/hc/src/common/up_stackframe.c b/nuttx/arch/hc/src/common/up_stackframe.c
new file mode 100644
index 000000000..0daa4f7da
--- /dev/null
+++ b/nuttx/arch/hc/src/common/up_stackframe.c
@@ -0,0 +1,133 @@
+/****************************************************************************
+ * arch/hc/src/common/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/* The CPU12 stack should be aligned at half-word (2 byte) boundaries. If
+ * necessary frame_size must be rounded up to the next boundary
+ */
+
+#define STACK_ALIGNMENT     2
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/mips/src/common/up_createstack.c b/nuttx/arch/mips/src/common/up_createstack.c
index 6109797a3..e2a73fc7d 100644
--- a/nuttx/arch/mips/src/common/up_createstack.c
+++ b/nuttx/arch/mips/src/common/up_createstack.c
@@ -60,14 +60,14 @@
  */
 
 #ifdef CONFIG_LIBC_FLOATINGPOINT
-#  define CONFIG_STACK_ALIGNMENT 8
+#  define STACK_ALIGNMENT   8
 #else
-#  define CONFIG_STACK_ALIGNMENT 4
+#  define STACK_ALIGNMENT   4
 #endif
 
 /* Stack alignment macros */
 
-#define STACK_ALIGN_MASK    (CONFIG_STACK_ALIGNMENT-1)
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
 #define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
 #define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
 
diff --git a/nuttx/arch/mips/src/common/up_stackframe.c b/nuttx/arch/mips/src/common/up_stackframe.c
new file mode 100644
index 000000000..9b473ecc6
--- /dev/null
+++ b/nuttx/arch/mips/src/common/up_stackframe.c
@@ -0,0 +1,136 @@
+/****************************************************************************
+ * arch/mips/src/common/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+/* MIPS requires at least a 4-byte stack alignment.  For floating point use, 
+ * however, the stack must be aligned to 8-byte addresses.
+ */
+
+#ifdef CONFIG_LIBC_FLOATINGPOINT
+#  define STACK_ALIGNMENT   8
+#else
+#  define STACK_ALIGNMENT   4
+#endif
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/mips/src/common/up_usestack.c b/nuttx/arch/mips/src/common/up_usestack.c
index b636a51d7..934ac8ed1 100644
--- a/nuttx/arch/mips/src/common/up_usestack.c
+++ b/nuttx/arch/mips/src/common/up_usestack.c
@@ -50,6 +50,26 @@
 #include "up_internal.h"
 
 /****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* MIPS requires at least a 4-byte stack alignment.  For floating point use, 
+ * however, the stack must be aligned to 8-byte addresses.
+ */
+
+#ifdef CONFIG_LIBC_FLOATINGPOINT
+#  define STACK_ALIGNMENT   8
+#else
+#  define STACK_ALIGNMENT   4
+#endif
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
  * Private Types
  ****************************************************************************/
 
@@ -107,21 +127,20 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
 
   tcb->stack_alloc_ptr = stack;
 
-  /* MIPS uses a push-down stack:  the stack grows
-   * toward loweraddresses in memory.  The stack pointer
-   * register, points to the lowest, valid work address
-   * (the "top" of the stack).  Items on the stack are
-   * referenced as positive word offsets from sp.
+  /* MIPS uses a push-down stack:  the stack grows toward loweraddresses in
+   * memory.  The stack pointer register, points to the lowest, valid work
+   * address (the "top" of the stack).  Items on the stack are referenced
+   * as positive word offsets from sp.
    */
 
   top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
 
-  /* The MIPS stack must be aligned at word (4 byte)
-   * boundaries. If necessary top_of_stack must be rounded
-   * down to the next boundary
+  /* The MIPS stack must be aligned at word (4 byte) or double word (8 byte)
+   * boundaries. If necessary top_of_stack must be rounded down to the
+   * next boundary
    */
 
-  top_of_stack &= ~3;
+  top_of_stack = STACK_ALIGN_DOWN(top_of_stack);
   size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
 
   /* Save the adjusted stack values in the struct tcb_s */
diff --git a/nuttx/arch/rgmp/src/nuttx.c b/nuttx/arch/rgmp/src/nuttx.c
index 79f97fcfc..f218b3f18 100644
--- a/nuttx/arch/rgmp/src/nuttx.c
+++ b/nuttx/arch/rgmp/src/nuttx.c
@@ -168,6 +168,31 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
     return OK;
 }
 
+#ifdef CONFIG_NUTTX_KERNEL
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = (frame_size + 3) & ~3;
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size) {
+      return NULL;
+  }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
+#endif
+
 void up_release_stack(struct tcb_s *dtcb, uint8_t ttype)
 {
   /* Is there a stack allocated? */
diff --git a/nuttx/arch/sh/src/common/up_stackframe.c b/nuttx/arch/sh/src/common/up_stackframe.c
new file mode 100644
index 000000000..b1ef4c6b4
--- /dev/null
+++ b/nuttx/arch/sh/src/common/up_stackframe.c
@@ -0,0 +1,132 @@
+/****************************************************************************
+ * arch/sh/src/common/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+/* The SH stack must be aligned at word (4 byte) boundaries. If necessary
+ * frame_size must be rounded up to the next boundary
+ */
+
+#define STACK_ALIGNMENT     4
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/sh/src/common/up_usestack.c b/nuttx/arch/sh/src/common/up_usestack.c
index bcce3261c..e0f348045 100644
--- a/nuttx/arch/sh/src/common/up_usestack.c
+++ b/nuttx/arch/sh/src/common/up_usestack.c
@@ -107,18 +107,16 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
  
   tcb->stack_alloc_ptr = stack;
 
-  /* The Arm7Tdmi uses a push-down stack:  the stack grows
-   * toward loweraddresses in memory.  The stack pointer
-   * register, points to the lowest, valid work address
-   * (the "top" of the stack).  Items on the stack are
-   * referenced as positive word offsets from sp.
+  /* The SH family uses a push-down stack:  the stack grows toward lower
+   * addresses in memory.  The stack pointer register, points to the
+   * lowest, valid work address (the "top" of the stack).  Items on the
+   * stack are referenced as positive word offsets from sp.
    */
 
   top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
 
-  /* The Arm7Tdmi stack must be aligned at word (4 byte)
-   * boundaries. If necessary top_of_stack must be rounded
-   * down to the next boundary
+  /* The SH stack must be aligned at word (4 byte) boundaries. If necessary
+   * top_of_stack must be rounded down to the next boundary
    */
 
   top_of_stack &= ~3;
diff --git a/nuttx/arch/sim/src/up_stackframe.c b/nuttx/arch/sim/src/up_stackframe.c
new file mode 100644
index 000000000..4d62e6ec0
--- /dev/null
+++ b/nuttx/arch/sim/src/up_stackframe.c
@@ -0,0 +1,133 @@
+/****************************************************************************
+ * arch/sim/src/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/* Use a stack alignment of 4 bytes.  If necessary frame_size must be rounded
+ * up to the next boundary
+ */
+
+#define STACK_ALIGNMENT     4
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/x86/src/i486/up_stackframe.c b/nuttx/arch/x86/src/i486/up_stackframe.c
new file mode 100644
index 000000000..ea4edc07a
--- /dev/null
+++ b/nuttx/arch/x86/src/i486/up_stackframe.c
@@ -0,0 +1,134 @@
+/****************************************************************************
+ * arch/x86/src/i486/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/* The initial stack point is aligned at word (4 byte) boundaries. If
+ * necessary frame_size must be rounded up to the next boundary to retain
+ * this alignment.
+ */
+
+#define STACK_ALIGNMENT     4
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/z16/src/common/up_createstack.c b/nuttx/arch/z16/src/common/up_createstack.c
index 2bd3a8951..69a413bde 100644
--- a/nuttx/arch/z16/src/common/up_createstack.c
+++ b/nuttx/arch/z16/src/common/up_createstack.c
@@ -171,18 +171,16 @@ int up_create_stack(FAR struct tcb_s *tcb, size_t stack_size, uint8_t ttype)
       memset(tcb->stack_alloc_ptr, 0xaa, stack_size);
 #endif
 
-      /* The ZNeo uses a push-down stack:  the stack grows
-       * toward loweraddresses in memory.  The stack pointer
-       * register, points to the lowest, valid work address
-       * (the "top" of the stack).  Items on the stack are
-       * referenced as positive word offsets from sp.
+      /* The ZNeo uses a push-down stack:  the stack grows toward lower
+       * addresses in memory.  The stack pointer register, points to the
+       * lowest, valid work address (the "top" of the stack).  Items on
+       * the stack are referenced as positive word offsets from sp.
        */
 
       top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
 
-      /* The ZNeo stack must be aligned at word (4 byte)
-       * boundaries. If necessary top_of_stack must be rounded
-       * down to the next boundary
+      /* Align the stack to word (4 byte) boundaries.  This is probably
+       * a greater alignement than is required.
        */
 
       top_of_stack &= ~3;
diff --git a/nuttx/arch/z16/src/common/up_stackframe.c b/nuttx/arch/z16/src/common/up_stackframe.c
new file mode 100644
index 000000000..c11106542
--- /dev/null
+++ b/nuttx/arch/z16/src/common/up_stackframe.c
@@ -0,0 +1,132 @@
+/****************************************************************************
+ * arch/z16/src/common/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+/* Align the stack to word (4 byte) boundaries.  This is probablya greater
+ * alignement than is required.
+ */
+
+#define STACK_ALIGNMENT     4
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/z16/src/common/up_usestack.c b/nuttx/arch/z16/src/common/up_usestack.c
index 7b5effc45..eb725b7fb 100644
--- a/nuttx/arch/z16/src/common/up_usestack.c
+++ b/nuttx/arch/z16/src/common/up_usestack.c
@@ -107,18 +107,16 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
 
   tcb->stack_alloc_ptr = stack;
 
-  /* The Arm7Tdmi uses a push-down stack:  the stack grows
-   * toward loweraddresses in memory.  The stack pointer
-   * register, points to the lowest, valid work address
-   * (the "top" of the stack).  Items on the stack are
-   * referenced as positive word offsets from sp.
+  /* The ZNEO uses a push-down stack:  the stack grows toward lower
+   * addresses in memory.  The stack pointer register, points to the
+   * lowest, valid work address (the "top" of the stack).  Items on
+   * the stack are referenced as positive word offsets from sp.
    */
 
   top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
 
-  /* The Arm7Tdmi stack must be aligned at word (4 byte)
-   * boundaries. If necessary top_of_stack must be rounded
-   * down to the next boundary
+  /* Align the stack to word (4 byte) boundaries.  This is probably
+   * a greater alignement than is required.
    */
 
   top_of_stack &= ~3;
diff --git a/nuttx/arch/z80/src/common/up_stackframe.c b/nuttx/arch/z80/src/common/up_stackframe.c
new file mode 100644
index 000000000..01a7b0881
--- /dev/null
+++ b/nuttx/arch/z80/src/common/up_stackframe.c
@@ -0,0 +1,132 @@
+/****************************************************************************
+ * arch/z80/src/common/up_stackframe.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+/* The Z80 stack does not need to be aligned.  Here is is aligned at word
+ * (4 byte) boundary.
+ */
+
+#define STACK_ALIGNMENT     4
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_stack_frame
+ *
+ * Description:
+ *   Allocate a stack frame in the TCB's stack to hold thread-specific data.
+ *   This function may be called anytime after up_create_stack() or
+ *   up_use_stack() have been called but before the task has been started.
+ *
+ *   Thread data may be kept in the stack (instead of in the TCB) if it is
+ *   accessed by the user code directory.  This includes such things as
+ *   argv[].  The stack memory is guaranteed to be in the same protection
+ *   domain as the thread.
+ *
+ *   The following TCB fields will be re-initialized:
+ *
+ *   - adj_stack_size: Stack size after removal of the stack frame from
+ *     the stack
+ *   - adj_stack_ptr: Adjusted initial stack pointer after the frame has
+ *     been removed from the stack.  This will still be the initial value
+ *     of the stack pointer when the task is started.
+ *
+ * Inputs:
+ *   - tcb:  The TCB of new task
+ *   - frame_size:  The size of the stack frame to allocate.
+ *
+ *  Returned Value:
+ *   - A pointer to bottom of the allocated stack frame.  NULL will be
+ *     returned on any failures.  The alignment of the returned value is
+ *     the same as the alignment of the stack itself.
+ *
+ ****************************************************************************/
+
+FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size)
+{
+  uintptr_t topaddr;
+
+  /* Align the frame_size */
+
+  frame_size = STACK_ALIGN_UP(frame_size);
+  
+  /* Is there already a stack allocated? Is it big enough? */
+
+  if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size)
+    {
+      return NULL;
+    }
+
+  /* Save the adjusted stack values in the struct tcb_s */
+
+  topaddr              = (uintptr_t)tcb->adj_stack_ptr - frame_size;
+  tcb->adj_stack_ptr   = (FAR void *)topaddr;
+  tcb->adj_stack_size -= frame_size;
+
+  return (FAR void *)(topaddr + sizeof(uint32_t));
+}
diff --git a/nuttx/arch/z80/src/common/up_usestack.c b/nuttx/arch/z80/src/common/up_usestack.c
index 095b4f5d5..414040ec2 100644
--- a/nuttx/arch/z80/src/common/up_usestack.c
+++ b/nuttx/arch/z80/src/common/up_usestack.c
@@ -106,18 +106,16 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
 
   tcb->stack_alloc_ptr = stack;
 
-  /* The Arm7Tdmi uses a push-down stack:  the stack grows
-   * toward loweraddresses in memory.  The stack pointer
-   * register, points to the lowest, valid work address
-   * (the "top" of the stack).  Items on the stack are
-   * referenced as positive word offsets from sp.
+  /* The Z80 uses a push-down stack:  the stack grows toward lower
+   * addresses in memory.  The stack pointer register, points to the
+   * lowest, valid work address (the "top" of the stack).  Items on
+   * the stack are* referenced as positive word offsets from sp.
    */
 
   top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
 
-  /* The Arm7Tdmi stack must be aligned at word (4 byte)
-   * boundaries. If necessary top_of_stack must be rounded
-   * down to the next boundary
+  /* The Z80 stack does not need to be aligned.  Here is is aligned at
+   * word (4 byte) boundary.
    */
 
   top_of_stack &= ~3;