feat(cpufeat): enable FEAT_SVE for FEAT_STATE_CHECKED
Add support for runtime detection (ENABLE_SVE_FOR_NS=2), by splitting
sve_supported() into an ID register reading function and a
second function to report the support status. That function considers
both build time settings and runtime information (if needed), and is
used before we do SVE specific setup.
Change the FVP platform default to the now supported dynamic
option (=2), so the right decision can be made by the code at runtime.
Change-Id: I1caaba2216e8e2a651452254944a003607503216
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 4483dd4..1ee07d9 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -428,7 +428,7 @@
mechanism. The default is 2 but is automatically disabled when the target
architecture is AArch32.
-- ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension
+- ``ENABLE_SVE_FOR_NS``: Numeric value to enable Scalable Vector Extension
(SVE) for the Non-secure world only. SVE is an optional architectural feature
for AArch64. Note that when SVE is enabled for the Non-secure world, access
to SIMD and floating-point functionality from the Secure world is disabled by
@@ -437,9 +437,10 @@
which are aliased by the SIMD and FP registers. The build option is not
compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an
assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` set to
- 1. The default is 1 but is automatically disabled when ENABLE_SME_FOR_NS=1
- since SME encompasses SVE. At this time, this build option cannot be used on
- systems that have SPM_MM enabled.
+ 1. This flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
+ mechanism. The default is 1 but is automatically disabled when
+ ENABLE_SME_FOR_NS=1 since SME encompasses SVE. At this time, this build
+ option cannot be used on systems that have SPM_MM enabled.
- ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world.
SVE is an optional architectural feature for AArch64. Note that this option