build: restrict usage of CTX_INCLUDE_EL2_REGS
CTX_INCLUDE_EL2_REGS is used to save/restore EL2 registers and
it should be only used when there is SPMD or RME enabled.
Make CTX_INCLUDE_EL2_REGS an internal macro and remove
from documentation.
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
Change-Id: I6a70edfd88163423ff0482de094601cf794246d6
diff --git a/docs/getting_started/build-internals.rst b/docs/getting_started/build-internals.rst
new file mode 100644
index 0000000..a015d71
--- /dev/null
+++ b/docs/getting_started/build-internals.rst
@@ -0,0 +1,14 @@
+Internal Build Options
+======================
+
+|TF-A| internally uses certain options that are not exposed directly through
+:ref:`build-options <build options>` but enabled or disabled indirectly and
+depends on certain options to be enabled or disabled.
+
+.. _build_options_internal:
+
+- ``CTX_INCLUDE_EL2_REGS``: This boolean option provides context save/restore
+ operations when entering/exiting an EL2 execution context. This is of primary
+ interest when Armv8.4-SecEL2 or RME extension is implemented.
+ Default is 0 (disabled). This option will be set to 1 (enabled) when ``SPD=spmd``
+ and ``SPMD_SPM_AT_SEL2`` is set or when ``ENABLE_RME`` is set to 1 (enabled).