[RTEMS Project] #3959: Add rtems_task_build()

[RTEMS trac]

#3959: Add rtems_task_build()
------------------------------+-----------------------------
  Reporter:  Sebastian Huber  |      Owner:  Sebastian Huber
      Type:  enhancement      |     Status:  assigned
  Priority:  normal           |  Milestone:  6.1
 Component:  rtems            |    Version:  6
  Severity:  normal           |   Keywords:
Blocked By:                   |   Blocking:
------------------------------+-----------------------------
 In RTEMS 5 a lot of development was done to allow a static allocation of
 resources provided by RTEMS and avoid the use of a heap. One missing piece
 is the support for statically allocated RTEMS tasks. The
 rtems_task_create() function allocates the task stack from a heap. We need
 an alternative function which allocates an RTEMS tasks with a user
 provided stack (similar to the POSIX threads). Proposed API:
 {{{
 /**
  * @brief The task configuration to build a task.
  */
 typedef struct {
   /**
    * @brief The name of the task.
    */
   rtems_name name;

   /**
    * @brief The initial priority of the task.
    */
   rtems_task_priority initial_priority;

   /**
    * @brief The task stack area begin address for the task.
    */
   void *stack_area;

   /**
    * @brief The task stack area size in bytes for the task.
    */
   size_t stack_size;

   /**
    * @brief The function to free the task stack area if the task gets
 deleted.
    */
   void ( *stack_free )( void * );

   /**
    * @brief The initial modes of the task.
    */
   rtems_mode initial_modes;

   /**
    * @brief The attribute set of the task.
    */
   rtems_attribute attribute_set;
 } rtems_task_config;

 /**
  * @brief Builds a task according to the specified configuration.
  *
  * @param config The task configuration.
  * @param[out] id The task identifier of the new task.
  *
  * @retval RTEMS_SUCCESSFUL Successful operation.
  * @retval RTEMS_INVALID_ADDRESS The id parameter is @c NULL.
  * @retval RTEMS_INVALID_NAME The task name is invalid.
  * @retval RTEMS_INVALID_PRIORITY The initial priority of the task is
 invalid.
  * @retval RTEMS_TOO_MANY No task is available.
  * @retval RTEMS_UNSATISFIED A task create extension failed.
  */
 rtems_status_code rtems_task_build(
   const rtems_task_config *config,
   rtems_id                *id
 );
 }}}

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Ticket URL: <http://devel.rtems.org/ticket/3959>
RTEMS Project <http://www.rtems.org/>
RTEMS Project