feat(rng-trap): add EL3 support for FEAT_RNG_TRAP
FEAT_RNG_TRAP introduces support for EL3 trapping of reads of the
RNDR and RNDRRS registers, which is enabled by setting the
SCR_EL3.TRNDR bit. This patch adds a new build flag
ENABLE_FEAT_RNG_TRAP that enables the feature.
This feature is supported only in AArch64 state from Armv8.5 onwards.
Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Change-Id: Ia9f17aef3444d3822bf03809036a1f668c9f2d89
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index b291d62..80593a1 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -313,7 +313,13 @@
- ``ENABLE_FEAT_RNG``: Numeric value to enable the ``FEAT_RNG`` extension.
``FEAT_RNG`` is an optional feature available on Arm v8.5 onwards. This
flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
- mechanism. Default is ``0``.
+ mechanism. Default value is ``0``.
+
+- ``ENABLE_FEAT_RNG_TRAP``: Numeric value to enable the ``FEAT_RNG_TRAP``
+ extension. This feature is only supported in AArch64 state. This flag can
+ take values 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism.
+ Default value is ``0``. ``FEAT_RNG_TRAP`` is an optional feature from
+ Armv8.5 onwards.
- ``ENABLE_FEAT_SB``: Numeric value to enable the ``FEAT_SB`` (Speculation
Barrier) extension allowing access to ``sb`` instruction. ``FEAT_SB`` is an