docs: integration: Improve FP arch documentation
Improve the documentation of FP arch for the platforms.
The documentation was saying this should be set for the platform, but
not in which way. For most platforms this must now be set
as an additional argument to the build as most platform have not
added this configuration.
Based on the existing mps2/an521 and mps3/an552 boards setting this
variable in the preload.cmake is the right way to set it.
CONFIG_TFM_FP_ARCH does not have a default value.
Change-Id: If229f9e7f9b4875869129e991d19830ad746b6cc
Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>
diff --git a/docs/integration_guide/source_structure/platform_ext_folder.rst b/docs/integration_guide/source_structure/platform_ext_folder.rst
index 774f095..4a95d7a 100644
--- a/docs/integration_guide/source_structure/platform_ext_folder.rst
+++ b/docs/integration_guide/source_structure/platform_ext_folder.rst
@@ -129,8 +129,17 @@
target has, if it has one. This maps exactly to the subdirectories of
``platform/ext/accelerator``
-- ``CONFIG_TFM_FP_ARCH_ASM``: The FPU architecture used by the target. For more details,
- please refer to :doc:`Floating-Point Support </integration_guide/tfm_fpu_support>`.
+- ``CONFIG_TFM_FP_ARCH``: The "FPU architecture" (Armclang) or "FP hardware"
+ (GNU) used by the target for compiling C source files. The value will be
+ transferred to ``-mfpu`` argument of GNUARM or ARMCLANG
+
+- ``CONFIG_TFM_FP_ARCH_ASM``: The "FPU architecture" (Armclang) used by the
+ target for assembling ASM source files. This value will be transferred to the
+ ``--fpu`` argument of ARMCLANG. This value is not used by GNUARM.
+
+For more details on ``CONFIG_TFM_FP_ARCH`` and ``CONFIG_TFM_FP_ARCH_ASM``,
+please refer to
+:doc:`Floating-Point Support </integration_guide/tfm_fpu_support>`.
Other than these particular cmake variables, it is permissible for the
``preload.cmake`` file to contain ``add_definitions`` statements, in order for
diff --git a/docs/integration_guide/tfm_fpu_support.rst b/docs/integration_guide/tfm_fpu_support.rst
index abcab5d..71dbc87 100644
--- a/docs/integration_guide/tfm_fpu_support.rst
+++ b/docs/integration_guide/tfm_fpu_support.rst
@@ -113,11 +113,9 @@
are: auto, fpv5-d16, fpv5-sp-d16, etc. For armclang, example value are: none,
softvfp, fpv5-d16, fpv5-sp-d16, etc.
- Default value of ``CONFIG_TFM_FP_ARCH`` for GNUARM compiler is fpv5-sp-d16.
-
- This parameter shall be specified by platform. Please check compiler
- reference manual and processor hardware manual for more details to set
- correct FPU configuration for platform.
+ This parameter shall be specified by platform in preload.cmake. Please check
+ compiler reference manual and processor hardware manual for more details to
+ set correct FPU configuration for platform.
* ``CONFIG_TFM_FP_ARCH_ASM`` specifies the target FPU architecture name shared
by Arm Compiler armasm and armlink. It is only used in the ``--fpu=`` argument