c-user: Clarify config options use

Update #3836.

3 files changed, 34 insertions, 5 deletions

diff --git a/c-user/config/general.rst b/c-user/config/general.rst
index 388a8bf..c366be3 100644
--- a/c-user/config/general.rst
+++ b/c-user/config/general.rst
@@ -375,9 +375,12 @@ DESCRIPTION:
 
 NOTES:
     If there are more processors available than configured, the rest will be
-    ignored.  In uniprocessor configuration, this configuration define is
     ignored.
 
+    This configuration option is only evaluated in SMP configurations (e.g. RTEMS
+    was built with the ``--enable-smp`` build configuration option).  In all
+    other configurations it has no effect.
+
 .. index:: CONFIGURE_MAXIMUM_THREAD_NAME_SIZE
 .. index:: maximum thread name size
 
diff --git a/c-user/config/mpci.rst b/c-user/config/mpci.rst
index a3b5e23..854600b 100644
--- a/c-user/config/mpci.rst
+++ b/c-user/config/mpci.rst
@@ -36,8 +36,10 @@ DESCRIPTION:
     options are assumed to be provided.
 
 NOTES:
-    This has no impact unless RTEMS was built with the
-    ``--enable-multiprocessing`` build configuration option.
+    This configuration option shall be undefined if the multiprocessing support
+    is not enabled (e.g. RTEMS was built without the ``--enable-multiprocessing``
+    build configuration option).  Otherwise a compile time error in the
+    configuration file will occur.
 
 .. index:: CONFIGURE_EXTRA_MPCI_RECEIVE_SERVER_STACK
 
@@ -73,7 +75,8 @@ DESCRIPTION:
     :ref:`CONFIGURE_MINIMUM_TASK_STACK_SIZE`.
 
 NOTES:
-    None.
+    This configuration option is only evaluated if
+    :ref:`CONFIGURE_MP_APPLICATION` is defined.
 
 .. index:: CONFIGURE_MP_MAXIMUM_GLOBAL_OBJECTS
 
@@ -103,6 +106,9 @@ NOTES:
     This value corresponds to the total number of objects which can be created
     with the ``RTEMS_GLOBAL`` attribute.
 
+    This configuration option is only evaluated if
+    :ref:`CONFIGURE_MP_APPLICATION` is defined.
+
 .. index:: CONFIGURE_MP_MAXIMUM_NODES
 
 .. _CONFIGURE_MP_MAXIMUM_NODES:
@@ -128,7 +134,8 @@ DESCRIPTION:
     a multiprocessor system.
 
 NOTES:
-    None.
+    This configuration option is only evaluated if
+    :ref:`CONFIGURE_MP_APPLICATION` is defined.
 
 .. index:: CONFIGURE_MP_MAXIMUM_PROXIES
 
@@ -161,6 +168,9 @@ NOTES:
     remote tasks/threads which can be blocked on objects on this node, see
     :ref:`MPCIProxies`.
 
+    This configuration option is only evaluated if
+    :ref:`CONFIGURE_MP_APPLICATION` is defined.
+
 .. index:: CONFIGURE_MP_MPCI_TABLE_POINTER
 
 .. _CONFIGURE_MP_MPCI_TABLE_POINTER:
@@ -190,6 +200,9 @@ NOTES:
     Multiprocessor System assuming the BSP provides the proper set of
     supporting methods.
 
+    This configuration option is only evaluated if
+    :ref:`CONFIGURE_MP_APPLICATION` is defined.
+
 .. index:: CONFIGURE_MP_NODE_NUMBER
 
 .. _CONFIGURE_MP_NODE_NUMBER:
@@ -219,3 +232,6 @@ NOTES:
     the Makefile variable ``NODE_NUMBER``. The same code is compiled with the
     ``NODE_NUMBER`` set to different values. The test programs behave
     differently based upon their node number.
+
+    This configuration option is only evaluated if
+    :ref:`CONFIGURE_MP_APPLICATION` is defined.
diff --git a/c-user/config/posix-api.rst b/c-user/config/posix-api.rst
index 0c84012..1359909 100644
--- a/c-user/config/posix-api.rst
+++ b/c-user/config/posix-api.rst
@@ -176,6 +176,11 @@ VALUE CONSTRAINTS:
       RTEMS Workspace size calculation carried out by ``<rtems/confdefs.h>`` does
       not overflow an integer of type ``uintptr_t``.
 
+    * It shall be zero if the POSIX API is not
+      enabled (e.g. RTEMS was built without the ``--enable-posix`` build
+      configuration option).  Otherwise a compile time error in the configuration
+      file will occur.
+
 DESCRIPTION:
     The value of this configuration option defines the maximum number of POSIX
     API Queued Signals that can be concurrently active.
@@ -366,6 +371,11 @@ VALUE CONSTRAINTS:
       object class, if the value passed to :c:func:`rtems_resource_unlimited`
       satisfies all other constraints of this configuration option.
 
+    * It shall be zero if the POSIX API is not
+      enabled (e.g. RTEMS was built without the ``--enable-posix`` build
+      configuration option).  Otherwise a compile time error in the configuration
+      file will occur.
+
 DESCRIPTION:
     The value of this configuration option defines the maximum number of POSIX
     API Timers that can be concurrently active.