diff --git a/arch/risc-v/src/mpfs/mpfs_allocateheap.c b/arch/risc-v/src/mpfs/mpfs_allocateheap.c
index f0e225cea2c..79ae761f53c 100755
--- a/arch/risc-v/src/mpfs/mpfs_allocateheap.c
+++ b/arch/risc-v/src/mpfs/mpfs_allocateheap.c
@@ -37,7 +37,19 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-#define KRAM_END CONFIG_RAM_END
+#ifdef CONFIG_MM_KERNEL_HEAP
+#define KRAM_END    ((uintptr_t)&__ksram_end)
+#else
+#define KRAM_END    CONFIG_RAM_END
+#endif
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#ifdef CONFIG_MM_KERNEL_HEAP
+extern uintptr_t    __ksram_end;
+#endif
 
 /****************************************************************************
  * Public Functions
@@ -75,8 +87,12 @@
  *   Kernel heap               Size determined by CONFIG_MM_KERNEL_HEAPSIZE
  *
  ****************************************************************************/
-#ifndef CONFIG_BUILD_KERNEL
-void up_allocate_heap(void **heap_start, size_t *heap_size)
+
+#ifdef CONFIG_BUILD_KERNEL
+void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
+#else
+void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
+#endif /* CONFIG_BUILD_KERNEL */
 {
 #if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_MM_KERNEL_HEAP)
   /* Get the size and position of the user-space heap.
@@ -102,7 +118,6 @@ void up_allocate_heap(void **heap_start, size_t *heap_size)
   *heap_size = KRAM_END - g_idle_topstack;
 #endif /* CONFIG_BUILD_PROTECTED && CONFIG_MM_KERNEL_HEAP */
 }
-#endif /* CONFIG_BUILD_KERNEL */
 
 /****************************************************************************
  * Name: up_allocate_kheap
@@ -114,7 +129,8 @@ void up_allocate_heap(void **heap_start, size_t *heap_size)
  *
  ****************************************************************************/
 
-#if !defined(CONFIG_BUILD_FLAT) && defined(CONFIG_MM_KERNEL_HEAP)
+#if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_MM_KERNEL_HEAP) && \
+    defined(__KERNEL__)
 void up_allocate_kheap(void **heap_start, size_t *heap_size)
 {
   /* Return the kernel heap settings. */
@@ -122,7 +138,7 @@ void up_allocate_kheap(void **heap_start, size_t *heap_size)
   *heap_start = (void *)g_idle_topstack;
   *heap_size = KRAM_END - g_idle_topstack;
 }
-#endif /* !CONFIG_BUILD_FLAT && CONFIG_MM_KERNEL_HEAP */
+#endif /* CONFIG_BUILD_PROTECTED && CONFIG_MM_KERNEL_HEAP */
 
 /****************************************************************************
  * Name: up_addregion