refactor(cpufeat): refactor arch feature build options
Current build infra defaults all cpufeats in defaults.mk and some
mandatory features are enabled in arch_features.mk and optional
arch features are enabled in platform specific makefile.
This fragmentation is sometime confusing to figure out which feature
is tied to which ARCH_MAJOR.ARCH_MINOR.
So, consolidating and grouping them for tracking and enabling makes
more sense. With this change we consolidate all ARCH feature handling
within arch_features.mk and disable all optional features that need
to be enabled to platform makefile.
This is an ongoing series of effort to consolidate and going forward
platform makefile should just specify ARCH_MAJOR and ARCH MINOR and
all mandatory feature should be selected based on arch_features.mk
any optional feature needed by the platform support can be enabled
by platform makefile.
It also makes it easier for platform ports to look upto arch_features.mk
and enable any optional feature that platform may need which are
supported from TF-A.
Change-Id: I18764008856d81414256b6cbabdfa42a16b8040d
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/docs/porting-guide.rst b/docs/porting-guide.rst
index 5a017ce..f612e1c 100644
--- a/docs/porting-guide.rst
+++ b/docs/porting-guide.rst
@@ -3463,6 +3463,15 @@
to ``no``. If any of the options ``EL3_PAYLOAD_BASE`` or ``PRELOADED_BL33_BASE``
are used, this flag will be set to ``no`` automatically.
+- **ARM_ARCH_MAJOR and ARM_ARCH_MINOR**
+ By default, ARM_ARCH_MAJOR.ARM_ARCH_MINOR is set to 8.0 in ``defaults.mk``,
+ if the platform makefile/build defines or uses the correct ARM_ARCH_MAJOR and
+ ARM_ARCH_MINOR then mandatory Architectural features available for that Arch
+ version will be enabled by default and any optional Arch feature supported by
+ the Architecture and available in TF-A can be enabled from platform specific
+ makefile. Look up to ``arch_features.mk`` for details pertaining to mandatory
+ and optional Arch specific features.
+
Platform include paths
----------------------