Added system task attribute to allow one to create a task with "0" priority

via the user api.

4 files changed, 40 insertions, 9 deletions

diff --git a/cpukit/rtems/include/rtems/rtems/attr.h b/cpukit/rtems/include/rtems/rtems/attr.h
index c5376540af..215b27f9a0 100644
--- a/cpukit/rtems/include/rtems/rtems/attr.h
+++ b/cpukit/rtems/include/rtems/rtems/attr.h
@@ -47,6 +47,9 @@ typedef unsigned32 rtems_attribute;
 #define RTEMS_NO_PRIORITY_CEILING 0x00000000
 #define RTEMS_PRIORITY_CEILING    0x00000040
 
+#define RTEMS_APPLICATION_TASK    0x00000000
+#define RTEMS_SYSTEM_TASK         0x00000080
+
 #if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
 #define ATTRIBUTES_NOT_SUPPORTED       0
 #else
diff --git a/cpukit/rtems/inline/rtems/rtems/attr.inl b/cpukit/rtems/inline/rtems/rtems/attr.inl
index f8f890ae04..3cec1edd3b 100644
--- a/cpukit/rtems/inline/rtems/rtems/attr.inl
+++ b/cpukit/rtems/inline/rtems/rtems/attr.inl
@@ -155,5 +155,22 @@ RTEMS_INLINE_ROUTINE boolean _Attributes_Is_priority_ceiling(
    return ( attribute_set & RTEMS_PRIORITY_CEILING );
 }
 
+/*PAGE
+ *
+ *  _Attributes_Is_system_task
+ *
+ *  DESCRIPTION:
+ *
+ *  This function returns TRUE if the system task attribute
+ *  is enabled in the attribute_set and FALSE otherwise.
+ */
+ 
+RTEMS_INLINE_ROUTINE boolean _Attributes_Is_system_task(
+  rtems_attribute attribute_set
+)
+{
+   return ( attribute_set & RTEMS_PRIORITY_CEILING );
+}
+
 #endif
 /* end of include file */
diff --git a/cpukit/rtems/macros/rtems/rtems/attr.inl b/cpukit/rtems/macros/rtems/rtems/attr.inl
index 844ac4f012..290e7f7870 100644
--- a/cpukit/rtems/macros/rtems/rtems/attr.inl
+++ b/cpukit/rtems/macros/rtems/rtems/attr.inl
@@ -87,5 +87,14 @@
 #define _Attributes_Is_priority_ceiling( _attribute_set ) \
   ( (_attribute_set) & RTEMS_PRIORITY_CEILING )
 
+/*PAGE
+ *
+ *  _Attributes_Is_system_task
+ *
+ */
+ 
+#define _Attributes_Is_system_task( _attribute_set ) \
+  ( (_attribute_set) & RTEMS_SYSTEM_TASK )
+
 #endif
 /* end of include file */
diff --git a/cpukit/rtems/src/tasks.c b/cpukit/rtems/src/tasks.c
index 81955cd305..723a769836 100644
--- a/cpukit/rtems/src/tasks.c
+++ b/cpukit/rtems/src/tasks.c
@@ -269,15 +269,6 @@ rtems_status_code rtems_task_create(
 #endif
 
   /*
-   *  Validate the RTEMS API priority and convert it to the core priority range.
-   */
-
-  if ( !_RTEMS_tasks_Priority_is_valid( initial_priority ) )
-    return RTEMS_INVALID_PRIORITY;
-
-  core_priority = _RTEMS_tasks_Priority_to_Core( initial_priority );
-
-  /*
    *  Fix the attribute set to match the attributes which
    *  this processor (1) requires and (2) is able to support.
    *  First add in the required flags for attribute_set
@@ -295,6 +286,17 @@ rtems_status_code rtems_task_create(
   else
     is_fp = FALSE;
 
+  /*
+   *  Validate the RTEMS API priority and convert it to the core priority range.
+   */
+
+  if ( !_Attributes_Is_system_task( the_attribute_set ) ) {
+    if ( !_RTEMS_tasks_Priority_is_valid( initial_priority ) )
+      return RTEMS_INVALID_PRIORITY;
+  }
+
+  core_priority = _RTEMS_tasks_Priority_to_Core( initial_priority );
+
   if ( _Attributes_Is_global( the_attribute_set ) ) {
 
     is_global = TRUE;