config: Add CONFIGURE_IDLE_TASK_STORAGE_SIZE

By default, allocate the IDLE task storage areas from the RTEMS Workspace.
This avoids having to estimate the thread-local storage size in the default
configuration.

Add the application configuration option CONFIGURE_IDLE_TASK_STORAGE_SIZE to
request a static allocation of the task storage area for IDLE tasks.

Update #3835.
Update #4524.

3 files changed, 57 insertions, 11 deletions

diff --git a/cpukit/include/rtems/score/interr.h b/cpukit/include/rtems/score/interr.h
index d0ecf0f5c8..f21e8d58a1 100644
--- a/cpukit/include/rtems/score/interr.h
+++ b/cpukit/include/rtems/score/interr.h
@@ -229,7 +229,8 @@ typedef enum {
   INTERNAL_ERROR_NO_MEMORY_FOR_PER_CPU_DATA = 40,
   INTERNAL_ERROR_TOO_LARGE_TLS_SIZE = 41,
   INTERNAL_ERROR_RTEMS_INIT_TASK_CONSTRUCT_FAILED = 42,
-  INTERNAL_ERROR_IDLE_THREAD_CREATE_FAILED = 43
+  INTERNAL_ERROR_IDLE_THREAD_CREATE_FAILED = 43,
+  INTERNAL_ERROR_NO_MEMORY_FOR_IDLE_TASK_STORAGE = 44
 } Internal_errors_Core_list;
 
 typedef CPU_Uint32ptr Internal_errors_t;
diff --git a/cpukit/include/rtems/score/stack.h b/cpukit/include/rtems/score/stack.h
index 7577ca0474..9326480373 100644
--- a/cpukit/include/rtems/score/stack.h
+++ b/cpukit/include/rtems/score/stack.h
@@ -11,8 +11,8 @@
  */
 
 /*
- *  COPYRIGHT (c) 1989-2006.
- *  On-Line Applications Research Corporation (OAR).
+ * Copyright (C) 2022 embedded brains GmbH
+ * Copyright (C) 1989, 2021 On-Line Applications Research Corporation (OAR)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -172,7 +172,57 @@ extern const Stack_Allocator_free _Stack_Allocator_free;
  */
 void _Stack_Allocator_do_initialize( void );
 
-/** @} */
+/**
+ * @brief Allocates the IDLE thread storage area from the workspace.
+ *
+ * If the thread storage area cannot be allocated, then the
+ * ::INTERNAL_ERROR_NO_MEMORY_FOR_IDLE_TASK_STACK fatal error will occur.
+ *
+ * @param unused is an unused parameter.
+ *
+ * @param stack_size[in] is pointer to a size_t object.  On function entry, the
+ *   object contains the size of the task storage area to allocate in bytes.
+ *
+ * @return Returns a pointer to the begin of the allocated task storage area.
+ */
+void *_Stack_Allocator_allocate_for_idle_workspace(
+  uint32_t  unused,
+  size_t   *storage_size
+);
+
+/**
+ * @brief The size in bytes of the idle thread storage area used by
+ *   _Stack_Allocator_allocate_for_idle_static().
+ *
+ * Application provided via <rtems/confdefs.h>.
+ */
+extern const size_t _Stack_Allocator_allocate_for_idle_storage_size;
+
+/**
+ * @brief The thread storage areas used by
+ *   _Stack_Allocator_allocate_for_idle_static().
+ *
+ * Application provided via <rtems/confdefs.h>.
+ */
+extern char _Stack_Allocator_allocate_for_idle_storage_areas[];
+
+/**
+ * @brief Allocates the IDLE thread storage from the memory statically
+ *   allocated by <rtems/confdefs.h>.
+ *
+ * @param cpu_index is the index of the CPU for the IDLE thread using this stack.
+ *
+ * @param stack_size[out] is pointer to a size_t object.  On function return, the
+ *   object value is set to the value of
+ *   ::_Stack_Allocator_allocate_for_idle_storage_size.
+ *
+ * @return Returns a pointer to the begin of the allocated task storage area.
+ */
+void *_Stack_Allocator_allocate_for_idle_static(
+  uint32_t  cpu_index,
+  size_t   *storage_size
+);
+
 /**
  * @brief The stack allocator allocate stack for idle thread handler.
  *
@@ -181,6 +231,8 @@ void _Stack_Allocator_do_initialize( void );
 extern const Stack_Allocator_allocate_for_idle
   _Stack_Allocator_allocate_for_idle;
 
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/cpukit/include/rtems/score/thread.h b/cpukit/include/rtems/score/thread.h
index f82d4b954c..2b4d6823f0 100644
--- a/cpukit/include/rtems/score/thread.h
+++ b/cpukit/include/rtems/score/thread.h
@@ -1186,13 +1186,6 @@ Thread_Information name##_Information = { \
   } \
 }
 
-/**
- * @brief The idle thread stacks.
- *
- * Provided by the application via <rtems/confdefs.h>.
- */
-extern char _Thread_Idle_stacks[];
-
 #if defined(RTEMS_MULTIPROCESSING)
 /**
  * @brief The configured thread control block.