c-user: Add event recording configuration

Update #3665.

c-user/configuring_a_system.rst

@@ -4813,6 +4813,64 @@ Note that selecting ``PCI_LIB_STATIC`` or ``PCI_LIB_PERIPHERAL`` but not
 defining ``pci_hb`` will reuslt in link errors. Note also that in these modes
 Plug & Play is not performed.
 
+Event Recording
+===============
+
+.. index:: CONFIGURE_RECORD_PER_PROCESSOR_ITEMS
+
+.. _CONFIGURE_RECORD_PER_PROCESSOR_ITEMS:
+
+CONFIGURE_RECORD_PER_PROCESSOR_ITEMS
+------------------------------------
+
+CONSTANT:
+    ``CONFIGURE_RECORD_PER_PROCESSOR_ITEMS``
+
+DATA TYPE:
+    Unsigned integer (``unsigned int``).
+
+RANGE:
+    A power of two greater than or equal to 16.
+
+DEFAULT VALUE:
+    This is not defined by default.
+
+DESCRIPTION:
+    If defined, then a record item buffer of the specified item count is
+    statically allocated for each configured processor
+    (:ref:`CONFIGURE_MAXIMUM_PROCESSORS <CONFIGURE_MAXIMUM_PROCESSORS>`).
+
+NOTES:
+    None.
+
+.. index:: CONFIGURE_RECORD_EXTENSIONS_ENABLED
+
+.. _CONFIGURE_RECORD_EXTENSIONS_ENABLED:
+
+CONFIGURE_RECORD_EXTENSIONS_ENABLED
+-----------------------------------
+
+CONSTANT:
+    ``CONFIGURE_RECORD_EXTENSIONS_ENABLED``
+
+DATA TYPE:
+    Boolean feature macro.
+
+RANGE:
+    Defined or undefined.
+
+DEFAULT VALUE:
+    This is not defined by default.
+
+DESCRIPTION:
+    If defined and :ref:`CONFIGURE_RECORD_PER_PROCESSOR_ITEMS
+    <CONFIGURE_RECORD_PER_PROCESSOR_ITEMS>` is also defined properly, then the
+    record extensions are enabled.
+
+NOTES:
+    The record extensions capture thread create, start, restart, delete,
+    switch, begin, exitted and terminate events.
+
 Go Tasks
 ========