1 files changed, 92 insertions, 0 deletions
diff --git a/cpukit/score/src/heap.c b/cpukit/score/src/heap.c
new file mode 100644
index 0000000000..6d6873ebed
--- /dev/null
+++ b/cpukit/score/src/heap.c
@@ -0,0 +1,92 @@
+/*
+ *  Heap Handler
+ *
+ *  COPYRIGHT (c) 1989-1999.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+
+#include <rtems/system.h>
+#include <rtems/score/sysstate.h>
+#include <rtems/score/heap.h>
+
+/*PAGE
+ *
+ *  _Heap_Initialize
+ *
+ *  This kernel routine initializes a heap.
+ *
+ *  Input parameters:
+ *    the_heap         - pointer to heap header
+ *    starting_address - starting address of heap
+ *    size             - size of heap
+ *    page_size        - allocatable unit of memory
+ *
+ *  Output parameters:
+ *    returns - maximum memory available if RTEMS_SUCCESSFUL
+ *    0       - otherwise
+ *
+ *    This is what a heap looks like in memory immediately
+ *    after initialization:
+ *
+ *            +--------------------------------+
+ *     0      |  size = 0      | status = used |  a.k.a.  dummy back flag
+ *            +--------------------------------+
+ *     4      |  size = size-8 | status = free |  a.k.a.  front flag
+ *            +--------------------------------+
+ *     8      |  next     = PERM HEAP_TAIL     |
+ *            +--------------------------------+
+ *    12      |  previous = PERM HEAP_HEAD     |
+ *            +--------------------------------+
+ *            |                                |
+ *            |      memory available          |
+ *            |       for allocation           |
+ *            |                                |
+ *            +--------------------------------+
+ *  size - 8  |  size = size-8 | status = free |  a.k.a.  back flag
+ *            +--------------------------------+
+ *  size - 4  |  size = 0      | status = used |  a.k.a.  dummy front flag
+ *            +--------------------------------+
+ */
+
+uint32_t   _Heap_Initialize(
+  Heap_Control        *the_heap,
+  void                *starting_address,
+  uint32_t             size,
+  uint32_t             page_size
+)
+{
+  Heap_Block        *the_block;
+  uint32_t           the_size;
+
+  if ( !_Heap_Is_page_size_valid( page_size ) ||
+       (size < HEAP_MINIMUM_SIZE) )
+    return 0;
+
+  the_heap->page_size = page_size;
+  the_size = size - HEAP_OVERHEAD;
+
+  the_block             = (Heap_Block *) starting_address;
+  the_block->back_flag  = HEAP_DUMMY_FLAG;
+  the_block->front_flag = the_size;
+  the_block->next       = _Heap_Tail( the_heap );
+  the_block->previous   = _Heap_Head( the_heap );
+
+  the_heap->start          = the_block;
+  the_heap->first          = the_block;
+  the_heap->permanent_null = NULL;
+  the_heap->last           = the_block;
+
+  the_block             = _Heap_Next_block( the_block );
+  the_block->back_flag  = the_size;
+  the_block->front_flag = HEAP_DUMMY_FLAG;
+  the_heap->final       = the_block;
+
+  return ( the_size - HEAP_BLOCK_USED_OVERHEAD );
+}