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

6 files changed, 115 insertions, 94 deletions

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