score: Work area initialization API change

The work areas (RTEMS work space and C program heap) will be initialized
now in a separate step and are no longer part of
rtems_initialize_data_structures().  Initialization is performed with
tables of Heap_Area entries.  This allows usage of scattered memory
areas present on various small scale micro-controllers.

The sbrk() support API changes also.  The bsp_sbrk_init() must now deal
with a minimum size for the first memory chunk to take the configured
work space size into account.

1 files changed, 58 insertions, 0 deletions

diff --git a/cpukit/libcsupport/src/rtems_heap_extend_via_sbrk.c b/cpukit/libcsupport/src/rtems_heap_extend_via_sbrk.c
new file mode 100644
index 0000000000..831626b3d5
--- /dev/null
+++ b/cpukit/libcsupport/src/rtems_heap_extend_via_sbrk.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2012 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * 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.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <unistd.h>
+
+#include <rtems/malloc.h>
+
+#include "malloc_p.h"
+
+ptrdiff_t RTEMS_Malloc_Sbrk_amount;
+
+void *rtems_heap_extend_via_sbrk(
+  Heap_Control *heap,
+  size_t alloc_size
+)
+{
+  ptrdiff_t sbrk_amount = RTEMS_Malloc_Sbrk_amount;
+  ptrdiff_t sbrk_size = (ptrdiff_t) alloc_size;
+  ptrdiff_t misaligned = sbrk_size % sbrk_amount;
+  void *return_this = NULL;
+
+  if ( misaligned != 0 ) {
+    sbrk_size += sbrk_amount - misaligned;
+  }
+
+  if ( sbrk_size > 0 && sbrk_amount > 0 ) {
+    void *area_begin = sbrk( sbrk_size );
+
+    if ( area_begin != (void *) -1 ) {
+      bool ok = _Protected_heap_Extend( heap, area_begin, sbrk_size );
+
+      if ( ok ) {
+        MSBUMP( space_available, sbrk_size );
+
+        return_this = _Protected_heap_Allocate( heap, alloc_size );
+      } else {
+        sbrk( -sbrk_size );
+      }
+    }
+  }
+
+  return return_this;
+}