Add MPU support for the LPC17xx family

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5731 42af7a65-404d-4744-a932-0658087f49c3

15 files changed, 637 insertions, 99 deletions

diff --git a/nuttx/arch/arm/Kconfig b/nuttx/arch/arm/Kconfig
index 683e23f36..a5e24e29a 100644
--- a/nuttx/arch/arm/Kconfig
+++ b/nuttx/arch/arm/Kconfig
@@ -216,6 +216,13 @@ config ARMV7M_MPU
 		Build in support for the ARM Cortex-M3/4 Memory Protection Unit (MPU).
 		Check your chip specifications first; not all Cortex-M3/4 chips support the MPU.
 
+config ARMV7M_MPU_NREGIONS
+	int "Number of MPU regions"
+	default 8
+	depends on ARMV7M_MPU
+	---help---
+	This is the number of protection regions supported by the MPU.
+
 config ARCH_HAVE_LOWVECTORS
 	bool
 
diff --git a/nuttx/arch/arm/src/armv7-m/up_mpu.c b/nuttx/arch/arm/src/armv7-m/up_mpu.c
index d4b04a444..2b8a8f994 100644
--- a/nuttx/arch/arm/src/armv7-m/up_mpu.c
+++ b/nuttx/arch/arm/src/armv7-m/up_mpu.c
@@ -48,6 +48,11 @@
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_ARMV7M_MPU_NREGIONS
+#  define CONFIG_ARMV7M_MPU_NREGIONS 8
+#endif
 
 /****************************************************************************
  * Private Data
@@ -84,13 +89,14 @@ static uint8_t g_region;
  *
  * Assumptions:
  *   - Regions are never deallocated
- *   - Regions are only allocated early in initialization, so nothing
- *     special is require;
+ *   - Regions are only allocated early in initialization, so no special
+ *     protection against re-entrancy is required;
  *
  ****************************************************************************/
 
 unsigned int mpu_allocregion(void)
 {
+  DEBUGASSERT(g_region < CONFIG_ARMV7M_MPU_NREGIONS);
   return (unsigned int)g_region++;
 }
 
diff --git a/nuttx/arch/arm/src/lpc17xx/Make.defs b/nuttx/arch/arm/src/lpc17xx/Make.defs
index b7bf38279..679e51a5f 100644
--- a/nuttx/arch/arm/src/lpc17xx/Make.defs
+++ b/nuttx/arch/arm/src/lpc17xx/Make.defs
@@ -63,6 +63,10 @@ ifeq ($(CONFIG_ARCH_MEMCPY),y)
 CMN_ASRCS += up_memcpy.S
 endif
 
+ifeq ($(CONFIG_NUTTX_KERNEL),y)
+CMN_CSRCS += up_mpu.c
+endif
+
 ifeq ($(CONFIG_NET),y)
 ifneq ($(CONFIG_LPC17_ETHERNET),y)
 CMN_CSRCS += up_etherstub.c
@@ -91,6 +95,10 @@ ifeq ($(CONFIG_ARMV7M_CMNVECTOR),y)
 CHIP_ASRCS += lpc17_vectors.S
 endif
 
+ifeq ($(CONFIG_NUTTX_KERNEL),y)
+CHIP_CSRCS += lpc17_userspace.c lpc17_mpuinit.c
+endif
+
 ifeq ($(CONFIG_LPC17_EMC),y)
 CHIP_CSRCS += lpc17_emc.c
 endif
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_allocateheap.c b/nuttx/arch/arm/src/lpc17xx/lpc17_allocateheap.c
index c49ceed36..b5cacce27 100644
--- a/nuttx/arch/arm/src/lpc17xx/lpc17_allocateheap.c
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_allocateheap.c
@@ -53,6 +53,7 @@
 #include "chip/lpc17_memorymap.h"
 #include "lpc17_emacram.h"
 #include "lpc17_ohciram.h"
+#include "lpc17_mpuinit.h"
 
 /****************************************************************************
  * Private Definitions
@@ -195,11 +196,84 @@
 
 void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
 {
+#if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP)
+  /* Get the unaligned size of the user-space heap */
+
+  uintptr_t ubase = (uintptr_t)g_heapbase + CONFIG_MM_KERNEL_HEAPSIZE;
+  size_t    usize = CONFIG_DRAM_END - ubase;
+  int       log2;
+
+  DEBUGASSERT(ubase < (uintptr_t)CONFIG_DRAM_END);
+
+  /* Adjust that size to account for MPU alignment requirements.
+   * NOTE that there is an implicit assumption that the CONFIG_DRAM_END
+   * is aligned to the MPU requirement.
+   */
+
+  log2  = (int)mpu_log2regionsize(usize);
+  DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
+
+  usize = (1 << log2);
+  ubase = CONFIG_DRAM_END - usize 
+
+  /* Return the user-space heap settings */
+
+  up_ledon(LED_HEAPALLOCATE);
+  *heap_start = (FAR void*)ubase;
+  *heap_size  = usize;
+
+  /* Allow user-mode access to the user heap memory */
+
+   lpc17_mpu_uheap((uintptr_t)ubase, usize);
+#else
+
+  /* Return the heap settings */
+
   up_ledon(LED_HEAPALLOCATE);
   *heap_start = (FAR void*)g_heapbase;
-  *heap_size = CONFIG_DRAM_END - g_heapbase;
+  *heap_size  = CONFIG_DRAM_END - g_heapbase;
+#endif
 }
 
+/****************************************************************************
+ * Name: up_allocate_kheap
+ *
+ * Description:
+ *   For the kernel build (CONFIG_NUTTX_KERNEL=y) with both kernel- and
+ *   user-space heaps (CONFIG_MM_KERNEL_HEAP=y), this function allocates
+ *   (and protects) the kernel-space heap.
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP)
+void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
+{
+  /* Get the unaligned size of the user-space heap */
+
+  uintptr_t ubase = (uintptr_t)g_heapbase + CONFIG_MM_KERNEL_HEAPSIZE;
+  size_t    usize = CONFIG_DRAM_END - ubase;
+  int       log2;
+
+  DEBUGASSERT(ubase < (uintptr_t)CONFIG_DRAM_END);
+
+  /* Adjust that size to account for MPU alignment requirements.
+   * NOTE that there is an implicit assumption that the CONFIG_DRAM_END
+   * is aligned to the MPU requirement.
+   */
+
+  log2  = (int)mpu_log2regionsize(usize);
+  DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
+
+  usize = (1 << log2);
+  ubase = CONFIG_DRAM_END - usize 
+
+  /* Return the kernel heap settings */
+
+  *heap_start = (FAR void*)g_heapbase;
+  *heap_size  = ubase - (uintptr_t)g_heapbase;
+}
+#endif
+
 /************************************************************************
  * Name: up_addregion
  *
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_mpuinit.c b/nuttx/arch/arm/src/lpc17xx/lpc17_mpuinit.c
new file mode 100644
index 000000000..0a90229e7
--- /dev/null
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_mpuinit.c
@@ -0,0 +1,124 @@
+/****************************************************************************
+ * arch/arm/src/common/lpc17_mpuinit.c
+ *
+ *   Copyright (C) 2011, 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 <assert.h>
+
+#include <nuttx/userspace.h>
+
+#include "mpu.h"
+#include "lp17_mpuinit.h"
+
+#if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_ARMV7M_MPU)
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+#ifndef MAX
+#  define MAX(a,b) a > b ? a : b
+#endif
+
+#ifndef MIN
+#  define MIN(a,b) a < b ? a : b
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: lpc17_mpuinitialize
+ *
+ * Description:
+ *   Configure the MPU to permit user-space access to only restricted SAM3U
+ *   resources.
+ *
+ ****************************************************************************/
+
+void lpc17_mpuinitialize(void)
+{
+  uintptr_t datastart = MIN(USERSPACE->us_datastart, USERSPACE->us_bssstart);
+  uintptr_t dataend   = MAX(USERSPACE->us_dataend,   USERSPACE->us_bssend);
+
+  DEBUGASSERT(USERSPACE->us_textend >= USERSPACE->us_textstart &&
+              dataend >= datastart);
+
+  /* Show MPU information */
+
+  mpu_showtype();
+
+  /* Configure user flash and SRAM space */
+
+  mpu_userflash(USERSPACE->us_textstart,
+                USERSPACE->us_textend - USERSPACE->us_textstart);
+
+  mpu_userintsram(datastart, dataend - datastart);
+
+  /* Then enable the MPU */
+
+  mpu_control(true, false, true);
+}
+
+/****************************************************************************
+ * Name: lpc17_mpu_uheap
+ *
+ * Description:
+ *  Map the user-heap region.
+ *
+ *  This logic may need an extension to handle external SDRAM).
+ *
+ ****************************************************************************/
+
+void lpc17_mpu_uheap(uintptr_t start, size_t size)
+{
+  mpu_userintsram(start, size);
+}
+
+#endif /* CONFIG_NUTTX_KERNEL && CONFIG_ARMV7M_MPU */
+
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_mpuinit.h b/nuttx/arch/arm/src/lpc17xx/lpc17_mpuinit.h
new file mode 100644
index 000000000..4d0e6944f
--- /dev/null
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_mpuinit.h
@@ -0,0 +1,90 @@
+/************************************************************************************
+ * arch/arm/src/lpc17xx/lpc17_mpuinit.h
+ *
+ *   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.
+ *
+ ************************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_LPC17XX_LPC17_MPUINIT_H
+#define __ARCH_ARM_SRC_LPC17XX_LPC17_MPUINIT_H
+
+/************************************************************************************
+ * Included Files
+ ************************************************************************************/
+
+#include <nuttx/config.h>
+
+/************************************************************************************
+ * Pre-processor Definitions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Types
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Data
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+/****************************************************************************
+ * Name: lpc17_mpuinitialize
+ *
+ * Description:
+ *   Configure the MPU to permit user-space access to only unrestricted MCU
+ *   resources.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NUTTX_KERNEL
+void lpc17_mpuinitialize(void);
+#else
+#  define lpc17_mpuinitialize()
+#endif
+
+/****************************************************************************
+ * Name: lpc17_mpu_uheap
+ *
+ * Description:
+ *  Map the user heap region.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NUTTX_KERNEL
+void lpc17_mpu_uheap(uintptr_t start, size_t size);
+#else
+#  define lpc17_mpu_uheap(start,size)
+#endif
+
+#endif /* __ARCH_ARM_SRC_LPC17XX_LPC17_MPUINIT_H */
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_start.c b/nuttx/arch/arm/src/lpc17xx/lpc17_start.c
index e13abe15c..e3e4013d0 100644
--- a/nuttx/arch/arm/src/lpc17xx/lpc17_start.c
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_start.c
@@ -2,7 +2,7 @@
  * arch/arm/src/lpc17xx/lpc17_start.c
  * arch/arm/src/chip/lpc17_start.c
  *
- *   Copyright (C) 2010, 2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2010, 2012-2013 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -52,6 +52,7 @@
 
 #include "lpc17_clockconfig.h"
 #include "lpc17_lowputc.h"
+#include "lpc17_userspace.h"
 
 #ifdef CONFIG_ARCH_FPU
 #  include "nvic.h"
@@ -230,10 +231,21 @@ void __start(void)
 #endif
   showprogress('D');
 
+  /* For the case of the separate user-/kernel-space build, perform whatever
+   * platform specific initialization of the user memory is required.
+   * Normally this just means initializing the user space .data and .bss
+   * segements.
+   */
+
+#ifdef CONFIG_NUTTX_KERNEL
+  lpc17_userspace();
+  showprogress('E');
+#endif
+
   /* Initialize onboard resources */
 
   lpc17_boardinitialize();
-  showprogress('E');
+  showprogress('F');
 
   /* Then start NuttX */
 
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_userspace.c b/nuttx/arch/arm/src/lpc17xx/lpc17_userspace.c
new file mode 100644
index 000000000..ffc935af3
--- /dev/null
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_userspace.c
@@ -0,0 +1,119 @@
+/****************************************************************************
+ * arch/arm/src/lpc17xx/lpc17_userspace.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 <stdint.h>
+#include <assert.h>
+
+#include <nuttx/userspace.h>
+
+#include "lpc17_mpuinit.h"
+#include "lpc17_userspace.h"
+
+#ifdef CONFIG_NUTTX_KERNEL
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: lpc17_userspace
+ *
+ * Description:
+ *   For the case of the separate user-/kernel-space build, perform whatever
+ *   platform specific initialization of the user memory is required.
+ *   Normally this just means initializing the user space .data and .bss
+ *   segments.
+ *
+ ****************************************************************************/
+
+void lpc17_userspace(void)
+{
+  uint8_t *src;
+  uint8_t *dest;
+  uint8_t *end;
+
+  /* Clear all of user-space .bss */
+
+  DEBUGASSERT(USERSPACE->us_bssstart != 0 && USERSPACE->us_bssend != 0 &&
+              USERSPACE->us_bssstart <= USERSPACE->us_bssend);
+
+  dest = (uint8_t*)USERSPACE->us_bssstart;
+  end  = (uint8_t*)USERSPACE->us_bssend;
+
+  while (dest != end)
+    {
+      *dest++ = 0;
+    }
+
+  /* Initialize all of user-space .data */
+
+  DEBUGASSERT(USERSPACE->us_datasource != 0 &&
+              USERSPACE->us_datastart != 0 && USERSPACE->us_dataend != 0 && 
+              USERSPACE->us_datastart <= USERSPACE->us_dataend);
+
+  src  = (uint8_t*)USERSPACE->us_datasource;
+  dest = (uint8_t*)USERSPACE->us_datastart;
+  end  = (uint8_t*)USERSPACE->us_dataend;
+
+  while (dest != end)
+    {
+      *dest++ = *src++;
+    }
+
+  /* Configure the MPU to permit user-space access to its FLASH and RAM */
+
+  lpc17_mpuinitialize();
+}
+
+#endif /* CONFIG_NUTTX_KERNEL */
+
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_userspace.h b/nuttx/arch/arm/src/lpc17xx/lpc17_userspace.h
new file mode 100644
index 000000000..c4d265cc0
--- /dev/null
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_userspace.h
@@ -0,0 +1,77 @@
+/************************************************************************************
+ * arch/arm/src/lpc17xx/lpc17_qei.h
+ *
+ *   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.
+ *
+ ************************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_LPC17XX_LPC17_USERSPACE_H
+#define __ARCH_ARM_SRC_LPC17XX_LPC17_USERSPACE_H
+
+/************************************************************************************
+ * Included Files
+ ************************************************************************************/
+
+#include <nuttx/config.h>
+#include "chip/lpc17_qei.h"
+
+/************************************************************************************
+ * Pre-processor Definitions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Types
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Data
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+/****************************************************************************
+ * Name: lpc17_userspace
+ *
+ * Description:
+ *   For the case of the separate user-/kernel-space build, perform whatever
+ *   platform specific initialization of the user memory is required.
+ *   Normally this just means initializing the user space .data and .bss
+ *   segments.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NUTTX_KERNEL
+void lpc17_userspace(void);
+#endif
+
+#endif /* __ARCH_ARM_SRC_LPC17XX_LPC17_USERSPACE_H */
diff --git a/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c b/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c
index 5b5c6b810..249777d69 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c
+++ b/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c
@@ -78,68 +78,6 @@
 #  warning "CONFIG_DRAM_END is before end of SRAM0... not all of SRAM0 used"
 #endif
 
-#ifdef CONFIG_MM_KERNEL_HEAPSIZE
-#  if CONFIG_MM_KERNEL_HEAPSIZE < (1 << 5)     /* Kernel heap size < 2**5 */
-#    define KHEAP_SIZE (1 << 4)                /*   Use size 2**4 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 6)   /* Kernel heap size < 2**6 */
-#    define KHEAP_SIZE (1 << 5)                /*   Use size 2**5 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 7)   /* Kernel heap size < 2**7 */
-#    define KHEAP_SIZE (1 << 6)                /*   Use size 2**6 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 8)   /* Kernel heap size < 2**8 */
-#    define KHEAP_SIZE (1 << 7)                /*   Use size 2**7 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 9)   /* Kernel heap size < 2**9 */
-#    define KHEAP_SIZE (1 << 8)                /*   Use size 2**8 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 10)  /* Kernel heap size < 2**10 */
-#    define KHEAP_SIZE (1 << 9)                /*   Use size 2**9 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 11)  /* Kernel heap size < 2**11 */
-#    define KHEAP_SIZE (1 << 10)               /*   Use size 2**10 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 12)  /* Kernel heap size < 2**12 */
-#    define KHEAP_SIZE (1 << 11)               /*   Use size 2**11 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 13)  /* Kernel heap size < 2**13 */
-#    define KHEAP_SIZE (1 << 12)               /*   Use size 2**12 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 14)  /* Kernel heap size < 2**14 */
-#    define KHEAP_SIZE (1 << 13)               /*   Use size 2**13 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 15)  /* Kernel heap size < 2**15 */
-#    define KHEAP_SIZE (1 << 14)               /*   Use size 2**14 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 16)  /* Kernel heap size < 2**16 */
-#    define KHEAP_SIZE (1 << 15)               /*   Use size 2**15 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 17)  /* Kernel heap size < 2**17 */
-#    define KHEAP_SIZE (1 << 16)               /*   Use size 2**16 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 18)  /* Kernel heap size < 2**18 */
-#    define KHEAP_SIZE (1 << 17)               /*   Use size 2**17 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 19)  /* Kernel heap size < 2**19 */
-#    define KHEAP_SIZE (1 << 18)               /*   Use size 2**18 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 20)  /* Kernel heap size < 2**20 */
-#    define KHEAP_SIZE (1 << 19)               /*   Use size 2**19 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 21)  /* Kernel heap size < 2**21 */
-#    define KHEAP_SIZE (1 << 20)               /*   Use size 2**20 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 22)  /* Kernel heap size < 2**22 */
-#    define KHEAP_SIZE (1 << 21)               /*   Use size 2**21 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 23)  /* Kernel heap size < 2**23 */
-#    define KHEAP_SIZE (1 << 22)               /*   Use size 2**22 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 24)  /* Kernel heap size < 2**24 */
-#    define KHEAP_SIZE (1 << 23)               /*   Use size 2**23 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 25)  /* Kernel heap size < 2**25 */
-#    define KHEAP_SIZE (1 << 24)               /*   Use size 2**24 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 26)  /* Kernel heap size < 2**26 */
-#    define KHEAP_SIZE (1 << 25)               /*   Use size 2**25 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 27)  /* Kernel heap size < 2**27 */
-#    define KHEAP_SIZE (1 << 26)               /*   Use size 2**26 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 28)  /* Kernel heap size < 2**28 */
-#    define KHEAP_SIZE (1 << 27)               /*   Use size 2**27 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 29)  /* Kernel heap size < 2**29 */
-#    define KHEAP_SIZE (1 << 28)               /*   Use size 2**28 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 30)  /* Kernel heap size < 2**30 */
-#    define KHEAP_SIZE (1 << 29)               /*   Use size 2**29 */
-#  elif CONFIG_MM_KERNEL_HEAPSIZE < (1 << 31)  /* Kernel heap size < 2**31 */
-#    define KHEAP_SIZE (1 << 30)               /*   Use size 2**30 */
-#  else
-#    define KHEAP_SIZE (1 << 31)               /*   Use size 2**31 */
-#  endif
-
-#  define KHEAP_MASK   (KHEAP_SIZE - 1)
-#endif
-
 /****************************************************************************
  * Private Data
  ****************************************************************************/
@@ -170,35 +108,41 @@
 void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
 {
 #if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP)
-  uintptr_t kbase = ((uintptr_t)g_heapbase + KHEAP_MASK) & ~KHEAP_MASK;
-  uintptr_t ubase = kbase + KHEAP_SIZE;
+  /* Get the unaligned size of the user-space heap */
+
+  uintptr_t ubase = (uintptr_t)g_heapbase + CONFIG_MM_KERNEL_HEAPSIZE;
   size_t    usize = CONFIG_DRAM_END - ubase;
+  int       log2;
 
   DEBUGASSERT(ubase < (uintptr_t)CONFIG_DRAM_END);
 
-  /* Return the heap settings */
+  /* Adjust that size to account for MPU alignment requirements.
+   * NOTE that there is an implicit assumption that the CONFIG_DRAM_END
+   * is aligned to the MPU requirement.
+   */
+
+  log2  = (int)mpu_log2regionsize(usize);
+  DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
+
+  usize = (1 << log2);
+  ubase = CONFIG_DRAM_END - usize 
+
+  /* Return the user-space heap settings */
 
   up_ledon(LED_HEAPALLOCATE);
   *heap_start = (FAR void*)ubase;
   *heap_size  = usize;
 
-  /* Allow access to the heap memory */
+  /* Allow user-mode access to the user heap memory */
 
    sam3u_mpu_uheap((uintptr_t)ubase, usize);
 #else
 
-  size_t size = CONFIG_DRAM_END - g_heapbase;
-
   /* Return the heap settings */
 
   up_ledon(LED_HEAPALLOCATE);
   *heap_start = (FAR void*)g_heapbase;
-  *heap_size  = size;
-
-  /* Allow user access to the user heap memory */
-
-   sam3u_mpu_uheap((uintptr_t)g_heapbase, size);
-   
+  *heap_size  = CONFIG_DRAM_END - g_heapbase;
 #endif
 }
 
@@ -215,14 +159,29 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
 #if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP)
 void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
 {
-  uintptr_t kbase = ((uintptr_t)g_heapbase + KHEAP_MASK) & ~KHEAP_MASK;
+  /* Get the unaligned size of the user-space heap */
 
-  DEBUGASSERT((kbase + KHEAP_SIZE) < (uintptr_t)CONFIG_DRAM_END);
+  uintptr_t ubase = (uintptr_t)g_heapbase + CONFIG_MM_KERNEL_HEAPSIZE;
+  size_t    usize = CONFIG_DRAM_END - ubase;
+  int       log2;
 
-  /* Return the heap settings */
+  DEBUGASSERT(ubase < (uintptr_t)CONFIG_DRAM_END);
+
+  /* Adjust that size to account for MPU alignment requirements.
+   * NOTE that there is an implicit assumption that the CONFIG_DRAM_END
+   * is aligned to the MPU requirement.
+   */
 
-  *heap_start = (FAR void*)kbase;
-  *heap_size  = KHEAP_SIZE;
+  log2  = (int)mpu_log2regionsize(usize);
+  DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
+
+  usize = (1 << log2);
+  ubase = CONFIG_DRAM_END - usize 
+
+  /* Return the kernel heap settings */
+
+  *heap_start = (FAR void*)g_heapbase;
+  *heap_size  = ubase - (uintptr_t)g_heapbase;
 }
 #endif
 
diff --git a/nuttx/arch/arm/src/sam3u/sam3u_internal.h b/nuttx/arch/arm/src/sam3u/sam3u_internal.h
index 14857bcf8..8953aa0c6 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_internal.h
+++ b/nuttx/arch/arm/src/sam3u/sam3u_internal.h
@@ -453,7 +453,7 @@ void sam3u_lowsetup(void);
  *   For the case of the separate user-/kernel-space build, perform whatever
  *   platform specific initialization of the user memory is required.
  *   Normally this just means initializing the user space .data and .bss
- *   segements.
+ *   segments.
  *
  ****************************************************************************/
 
@@ -465,7 +465,7 @@ void sam3u_userspace(void);
  * Name: sam3u_mpuinitialize
  *
  * Description:
- *   Configure the MPU to permit user-space access to only restricted SAM3U
+ *   Configure the MPU to permit user-space access to only unrestricted SAM3U
  *   resources.
  *
  ****************************************************************************/
diff --git a/nuttx/arch/arm/src/sam3u/sam3u_mpuinit.c b/nuttx/arch/arm/src/sam3u/sam3u_mpuinit.c
index 1e1a564d5..f3e18ad05 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_mpuinit.c
+++ b/nuttx/arch/arm/src/sam3u/sam3u_mpuinit.c
@@ -45,7 +45,7 @@
 
 #include "mpu.h"
 
-#ifdef CONFIG_NUTTX_KERNEL
+#if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_ARMV7M_MPU)
 
 /****************************************************************************
  * Private Definitions
@@ -105,12 +105,12 @@ void sam3u_mpuinitialize(void)
 }
 
 /****************************************************************************
- * Name: sam3u_mpu_uheap and sam3u_mpu_uheap
+ * Name: sam3u_mpu_uheap
  *
  * Description:
- *  Map a user- or kernel-heap region.
+ *  Map the user-heap region.
  *
- *  This logic may need an extension to handle external SRAM).
+ *  This logic may need an extension to handle external SDRAM).
  *
  ****************************************************************************/
 
@@ -119,5 +119,5 @@ void sam3u_mpu_uheap(uintptr_t start, size_t size)
   mpu_userintsram(start, size);
 }
 
-#endif /* CONFIG_NUTTX_KERNEL */
+#endif /* CONFIG_NUTTX_KERNEL && CONFIG_ARMV7M_MPU */
 
diff --git a/nuttx/arch/arm/src/sam3u/sam3u_start.c b/nuttx/arch/arm/src/sam3u/sam3u_start.c
index aceda2c46..dceb65ab2 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_start.c
+++ b/nuttx/arch/arm/src/sam3u/sam3u_start.c
@@ -142,12 +142,13 @@ void __start(void)
 
 #ifdef CONFIG_NUTTX_KERNEL
   sam3u_userspace();
+  showprogress('E');
 #endif
 
   /* Initialize onboard resources */
 
   sam3u_boardinitialize();
-  showprogress('E');
+  showprogress('F');
 
   /* Then start NuttX */
 
diff --git a/nuttx/arch/arm/src/sam3u/sam3u_userspace.c b/nuttx/arch/arm/src/sam3u/sam3u_userspace.c
index 89a2a27ed..1450e27a9 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_userspace.c
+++ b/nuttx/arch/arm/src/sam3u/sam3u_userspace.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * arch/arm/src/common/sam3u_userspace.c
+ * arch/arm/src/sam3u/sam3u_userspace.c
  *
  *   Copyright (C) 2011, 2013 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
@@ -71,7 +71,7 @@
  *   For the case of the separate user-/kernel-space build, perform whatever
  *   platform specific initialization of the user memory is required.
  *   Normally this just means initializing the user space .data and .bss
- *   segements.
+ *   segments.
  *
  ****************************************************************************/
 
diff --git a/nuttx/arch/arm/src/sam3u/sam3u_vectors.S b/nuttx/arch/arm/src/sam3u/sam3u_vectors.S
index 53e2f636c..ec0287e34 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_vectors.S
+++ b/nuttx/arch/arm/src/sam3u/sam3u_vectors.S
@@ -39,6 +39,7 @@
  ************************************************************************************************/
 
 #include <nuttx/config.h>
+
 #include <arch/irq.h>
 
 /************************************************************************************************
@@ -240,13 +241,18 @@ sam3u_common:
 	 */
 
 	adds	r2, r14, #3				/* If R14=0xfffffffd, then r2 == 0 */
-	ite		ne						/* Next two instructions are condition */
+	ite		ne						/* Next two instructions are conditional */
 	mrsne	r1, msp					/* R1=The main stack pointer */
 	mrseq	r1, psp					/* R1=The process stack pointer */
 #else
 	mrs		r1, msp					/* R1=The main stack pointer */
 #endif
 
+	/* r1 holds the value of the stack pointer AFTER the excption handling logic
+	 * pushed the various registers onto the stack.  Get r2 = the value of the
+	 * stack pointer BEFORE the interrupt modified it.
+	 */
+
 	mov		r2, r1					/* R2=Copy of the main/process stack pointer */
 	add		r2, #HW_XCPT_SIZE		/* R2=MSP/PSP before the interrupt was taken */
 #ifdef CONFIG_ARMV7M_USEBASEPRI
@@ -254,6 +260,22 @@ sam3u_common:
 #else
 	mrs		r3, primask				/* R3=Current PRIMASK setting */
 #endif
+
+#ifdef CONFIG_ARCH_FPU
+	/* Skip over the block of memory reserved for floating pointer register save.
+	 * Lazy FPU register saving is used.  FPU registers will be saved in this
+	 * block only if a context switch occurs (this means, of course, that the FPU
+	 * cannot be used in interrupt processing).
+	 */
+
+	sub		r1, #(4*SW_FPU_REGS)
+#endif
+
+	/* Save the the remaining registers on the stack after the registers pushed
+	 * by the exception handling logic. r2=SP and r3=primask or basepri, r4-r11,
+	 * r14=register values.
+	 */
+
 #ifdef CONFIG_NUTTX_KERNEL
 	stmdb	r1!, {r2-r11,r14}		/* Save the remaining registers plus the SP value */
 #else
@@ -290,17 +312,36 @@ sam3u_common:
 	cmp		r0, r1					/* Context switch? */
 	beq		1f						/* Branch if no context switch */
 
+	/* We are returning with a pending context switch.
+	 *
+	 * If the FPU is enabled, then we will need to restore FPU registers.
+	 * This is not done in normal interrupt save/restore because the cost
+	 * is prohibitive.  This is only done when switching contexts.  A
+	 * consequence of this is that floating point operations may not be
+	 * performed in interrupt handling logic.
+	 *
+	 * Here:
+	 *   r0 = Address of the register save area
+	
+	 * NOTE: It is a requirement that up_restorefpu() preserve the value of
+	 * r0!
+	 */
+
+#ifdef CONFIG_ARCH_FPU
+	bl		up_restorefpu			/* Restore the FPU registers */
+#endif
+
 	/* We are returning with a pending context switch.  This case is different
 	 * because in this case, the register save structure does not lie on the
 	 * stack but, rather, are within a TCB structure.  We'll have to copy some
 	 * values to the stack.
 	 */
 
-	add	r1, r0, #SW_XCPT_SIZE		/* R1=Address of HW save area in reg array */
+	add		r1, r0, #SW_XCPT_SIZE	/* R1=Address of HW save area in reg array */
 	ldmia	r1, {r4-r11}			/* Fetch eight registers in HW save area */
-	ldr	r1, [r0, #(4*REG_SP)]		/* R1=Value of SP before interrupt */
+	ldr		r1, [r0, #(4*REG_SP)]	/* R1=Value of SP before interrupt */
 	stmdb	r1!, {r4-r11}			/* Store eight registers in HW save area */
-#ifdef CONFIG_NUTTX_KERNEL 
+#ifdef CONFIG_NUTTX_KERNEL
 	ldmia	r0, {r2-r11,r14}		/* Recover R4-R11, r14 + 2 temp values */
 #else
 	ldmia	r0, {r2-r11}			/* Recover R4-R11 + 2 temp values */
@@ -309,13 +350,33 @@ sam3u_common:
 
 	/* We are returning with no context switch.  We simply need to "unwind"
 	 * the same stack frame that we created
+	 *
+	 * Here:
+	 *   r1 = Address of the return stack (same as r0)
 	 */
 1:
-#ifdef CONFIG_NUTTX_KERNEL 
+#ifdef CONFIG_NUTTX_KERNEL
 	ldmia	r1!, {r2-r11,r14}		/* Recover R4-R11, r14 + 2 temp values */
 #else
 	ldmia	r1!, {r2-r11}			/* Recover R4-R11 + 2 temp values */
 #endif
+
+#ifdef CONFIG_ARCH_FPU
+	/* Skip over the block of memory reserved for floating pointer register
+	 * save. Then R1 is the address of the HW save area
+	 */
+
+	add		r1, #(4*SW_FPU_REGS)
+#endif
+
+	/* Set up to return from the exception
+	 *
+	 * Here:
+	 *   r1 = Address on the target thread's stack position at the start of
+	 *        the registers saved by hardware
+	 *   r3 = primask or basepri
+	 *   r4-r11 = restored register values
+	 */
 2:
 #ifdef CONFIG_NUTTX_KERNEL
 	/* The EXC_RETURN value will be 0xfffffff9 (privileged thread) or 0xfffffff1