feat(tcr2): support FEAT_TCR2
Arm v8.9 introduces FEAT_TCR2, adding extended translation control
registers. Support this, context switching TCR2_EL2 and disabling
traps so lower ELs can access the new registers.
Change the FVP platform to default to handling this as a dynamic option so
the right decision can be made by the code at runtime.
Signed-off-by: Mark Brown <broonie@kernel.org>
Change-Id: I297452acd8646d58bac64fc15e05b06a543e5148
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index a285d31..38efe9e 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -348,6 +348,13 @@
values 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism.
Default value is ``0``.
+- ``ENABLE_FEAT_TCR2``: Numeric value to set the bit SCR_EL3.ENTCR2 in EL3 to
+ allow access to TCR2_EL2 (extended translation control) from EL2 as
+ well as adding TCR2_EL2 to the EL2 context save/restore operations. Its a
+ mandatory architectural feature and is enabled from v8.9 and upwards. This
+ flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
+ mechanism. Default value is ``0``.
+
- ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO)
support in GCC for TF-A. This option is currently only supported for
AArch64. Default is 0.