Rename g_heapbase to g_idle_topstack; Fix kernel build heap allocation which cannot use g_heapbase

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5739 42af7a65-404d-4744-a932-0658087f49c3

2 files changed, 22 insertions, 14 deletions

diff --git a/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c b/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c
index 86d5fbf36..576fae802 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c
+++ b/nuttx/arch/arm/src/sam3u/sam3u_allocateheap.c
@@ -109,9 +109,12 @@
 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 */
+  /* Get the unaligned size and position of the user-space heap.
+   * This heap begins after the user-space .bss section at an offset
+   * of CONFIG_MM_KERNEL_HEAPSIZE (subject to alignment).
+   */
 
-  uintptr_t ubase = (uintptr_t)g_heapbase + CONFIG_MM_KERNEL_HEAPSIZE;
+  uintptr_t ubase = (uintptr_t)USERSPACE->us_bssend + CONFIG_MM_KERNEL_HEAPSIZE;
   size_t    usize = CONFIG_DRAM_END - ubase;
   int       log2;
 
@@ -142,8 +145,8 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
   /* Return the heap settings */
 
   up_ledon(LED_HEAPALLOCATE);
-  *heap_start = (FAR void*)g_heapbase;
-  *heap_size  = CONFIG_DRAM_END - g_heapbase;
+  *heap_start = (FAR void*)g_idle_topstack;
+  *heap_size  = CONFIG_DRAM_END - g_idle_topstack;
 #endif
 }
 
@@ -160,9 +163,12 @@ 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)
 {
-  /* Get the unaligned size of the user-space heap */
+  /* Get the unaligned size and position of the user-space heap.
+   * This heap begins after the user-space .bss section at an offset
+   * of CONFIG_MM_KERNEL_HEAPSIZE (subject to alignment).
+   */
 
-  uintptr_t ubase = (uintptr_t)g_heapbase + CONFIG_MM_KERNEL_HEAPSIZE;
+  uintptr_t ubase = (uintptr_t)USERSPACE->us_bssend + CONFIG_MM_KERNEL_HEAPSIZE;
   size_t    usize = CONFIG_DRAM_END - ubase;
   int       log2;
 
@@ -179,10 +185,12 @@ void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
   usize = (1 << log2);
   ubase = CONFIG_DRAM_END - usize;
 
-  /* Return the kernel heap settings */
+  /* Return the kernel heap settings (i.e., the part of the heap region
+   * that was not dedicated to the user heap).
+   */
 
-  *heap_start = (FAR void*)g_heapbase;
-  *heap_size  = ubase - (uintptr_t)g_heapbase;
+  *heap_start = (FAR void*)USERSPACE->us_bssend;
+  *heap_size  = ubase - (uintptr_t)USERSPACE->us_bssend;
 }
 #endif
 
diff --git a/nuttx/arch/arm/src/sam3u/sam3u_vectors.S b/nuttx/arch/arm/src/sam3u/sam3u_vectors.S
index ec0287e34..eba6edd3a 100644
--- a/nuttx/arch/arm/src/sam3u/sam3u_vectors.S
+++ b/nuttx/arch/arm/src/sam3u/sam3u_vectors.S
@@ -443,13 +443,13 @@ g_intstackbase:
  * and is of size CONFIG_IDLETHREAD_STACKSIZE.  The IDLE thread is the thread that
  * the system boots on and, eventually, becomes the idle, do nothing task that runs
  * only when there is nothing else to run.  The heap continues from there until the
- * end of memory.  See g_heapbase below.
+ * end of memory.  See g_idle_topstack below.
  */
 
-	.globl	g_heapbase
-	.type	g_heapbase, object
-g_heapbase:
+	.globl	g_idle_topstack
+	.type	g_idle_topstack, object
+g_idle_topstack:
 	.word	HEAP_BASE
-	.size	g_heapbase, .-g_heapbase
+	.size	g_idle_topstack, .-g_idle_topstack
 
 	.end