Index: /soft/giet_vm/giet_libs/malloc.h
===================================================================
--- /soft/giet_vm/giet_libs/malloc.h	(revision 549)
+++ /soft/giet_vm/giet_libs/malloc.h	(revision 550)
@@ -6,8 +6,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 // Initialisation policy:
-//   Each heap(x,y) structure is initialized by the malloc() or remote_malloc()
-//   function, when this function is called the first time.
-//   The function hep_init() initialise the free blocks linked lists as 
-//   explained below.
+//   The user application must initialize the heap(x,y) structure before
+//   using the malloc() or remote_malloc() functions, and this initialization
+//   must be done by a single task.
 ////////////////////////////////////////////////////////////////////////////////
 // Free blocks organisation:
@@ -46,5 +45,5 @@
 // - Each allocated block is registered in an alloc[] array of unsigned char.
 // - This registration is required by the free() operation, because the size
-//   of the allocated block must obtained from the base address of the block.  
+//   of the allocated block must be obtained from the base address of the block.  
 // - The number of entries in this array is equal to the max number
 //   of allocated block is : heap_size / 128.
Index: /soft/giet_vm/giet_libs/stdio.c
===================================================================
--- /soft/giet_vm/giet_libs/stdio.c	(revision 549)
+++ /soft/giet_vm/giet_libs/stdio.c	(revision 550)
@@ -768,8 +768,10 @@
                    unsigned int  flags )
 {
-    return sys_call( SYSCALL_FAT_OPEN, 
-                     (unsigned int)pathname, 
-                     flags,
-                     0, 0 );
+    int ret = sys_call( SYSCALL_FAT_OPEN, 
+                        (unsigned int)pathname, 
+                        flags,
+                        0, 0 );
+    if ( ret < 0 ) giet_exit("error in giet_fat_open()");
+    return ret;
 }
 
Index: /soft/giet_vm/giet_libs/stdio.h
===================================================================
--- /soft/giet_vm/giet_libs/stdio.h	(revision 549)
+++ /soft/giet_vm/giet_libs/stdio.h	(revision 550)
@@ -280,6 +280,6 @@
 //////////////////////////////////////////////////////////////////////////
 
-extern int giet_fat_open(  const char*  pathname,
-                           unsigned int flags );
+extern int  giet_fat_open(  const char*  pathname,
+                            unsigned int flags );
 
 extern void giet_fat_read(  unsigned int fd,