1 files changed, 112 insertions, 0 deletions
diff --git a/cpukit/libcsupport/src/malloc_sbrk_helpers.c b/cpukit/libcsupport/src/malloc_sbrk_helpers.c
new file mode 100644
index 0000000000..e917fd36af
--- /dev/null
+++ b/cpukit/libcsupport/src/malloc_sbrk_helpers.c
@@ -0,0 +1,112 @@
+/*
+ *  RTEMS Malloc -- SBRK Support Plugin
+ *
+ *  COPYRIGHT (c) 1989-2007.
+ *  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.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <unistd.h> /* sbrk */
+
+#include <rtems.h>
+#include <rtems/malloc.h>
+#include "malloc_p.h"
+
+#include <errno.h>
+
+size_t  RTEMS_Malloc_Sbrk_amount;
+
+void *malloc_sbrk_initialize(
+  void  *starting_address,
+  size_t length
+)
+{
+  uintptr_t     old_address;
+  uintptr_t     uaddress;
+
+  RTEMS_Malloc_Sbrk_amount = length;
+
+  /*
+   * If the starting address is 0 then we are to attempt to
+   * get length worth of memory using sbrk. Make sure we
+   * align the address that we get back.
+   */
+
+  if (!starting_address) {
+    uaddress = (uintptr_t)sbrk(length);
+
+    if (uaddress == (uintptr_t) -1) {
+      rtems_fatal_error_occurred( RTEMS_NO_MEMORY );
+      /* DOES NOT RETURN!!! */
+    }
+
+    if (uaddress & (CPU_HEAP_ALIGNMENT-1)) {
+      old_address = uaddress;
+      uaddress = (uaddress + CPU_HEAP_ALIGNMENT) & ~(CPU_HEAP_ALIGNMENT-1);
+
+      /*
+       * adjust the length by whatever we aligned by
+       */
+      length -= uaddress - old_address;
+    }
+
+    starting_address = (void *)uaddress;
+  }
+  return starting_address;
+}
+
+void *malloc_sbrk_extend_and_allocate(
+  size_t size
+)
+{
+  uint32_t  sbrk_amount;
+  void     *starting_address;
+  uint32_t  the_size;
+  void     *return_this;
+
+  /*
+   *  Round to the "requested sbrk amount" so hopefully we won't have
+   *  to grow again for a while.  This effectively does sbrk() calls
+   *  in "page" amounts.
+   */
+
+  sbrk_amount = RTEMS_Malloc_Sbrk_amount;
+
+  if ( sbrk_amount == 0 )
+    return (void *) 0;
+
+  the_size = ((size + sbrk_amount) / sbrk_amount * sbrk_amount);
+
+  starting_address = (void *) sbrk(the_size);
+  if ( starting_address == (void*) -1 )
+    return (void *) 0;
+
+  if ( !_Protected_heap_Extend(
+          RTEMS_Malloc_Heap, starting_address, the_size) ) {
+    sbrk(-the_size);
+    errno = ENOMEM;
+    return (void *) 0;
+  }
+
+  MSBUMP(space_available, the_size);
+
+  return_this = _Protected_heap_Allocate( RTEMS_Malloc_Heap, size );
+  return return_this;
+}
+
+
+rtems_malloc_sbrk_functions_t rtems_malloc_sbrk_helpers_table = {
+  malloc_sbrk_initialize,
+  malloc_sbrk_extend_and_allocate
+};
+
+