docs: el3 token signing
Add documentation for the feature where EL3 can be used to sign realm
attestation token requests using RMM_EL3_TOKEN_SIGN command.
This patch also adds documentation for the RMM_EL3_FEATURES features
command that can be used to discover support for features such as
RMM_EL3_TOKEN_SIGN.
Change-Id: Iab5a157761ed17931210c3702f813198fc9c4b3a
Signed-off-by: Raghu Krishnamurthy <raghupathyk@nvidia.com>
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 772447a..cd10cd6 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -1343,6 +1343,13 @@
Management Extension. This flag can take the values 0 to 2, to align with
the ``ENABLE_FEAT`` mechanism. Default value is 0.
+- ``RMMD_ENABLE_EL3_TOKEN_SIGN``: Numeric value to enable support for singing
+ realm attestation token signing requests in EL3. This flag can take the
+ values 0 and 1. The default value is ``0``. When set to ``1``, this option
+ enables additional RMMD SMCs to push and pop requests for signing to
+ EL3 along with platform hooks that must be implemented to service those
+ requests and responses.
+
- ``ENABLE_SME_FOR_NS``: Numeric value to enable Scalable Matrix Extension
(SME), SVE, and FPU/SIMD for the non-secure world only. These features share
registers so are enabled together. Using this option without