docs: integration_guide: Improve FP arch documentation
Improve the documentation of FP arch for the platforms.
Add related description of 'CONFIG_TFM_FP_ARCH_ASM' used to
specify '--fpu' option for armasm and armlink. Add related
description of 'CONFIG_TFM_FP_ARCH' for armclang.
Signed-off-by: Chendi Sun <chendi.sun@arm.com>
Change-Id: Idb0f78f88e0ad8f73ebe80cf0b62a65af4ef907b
diff --git a/docs/integration_guide/tfm_fpu_support.rst b/docs/integration_guide/tfm_fpu_support.rst
index 6ebf7ce..abcab5d 100644
--- a/docs/integration_guide/tfm_fpu_support.rst
+++ b/docs/integration_guide/tfm_fpu_support.rst
@@ -18,6 +18,9 @@
support SFN model.
* Support Armv8-M mainline.
* Support isolation level 1,2,3.
+* Support Arm Compiler for Embedded [10]_. ``Arm Compiler for Embedded 6.17``
+ and later version shall be used to mitigate VLLDM instruction security
+ vulnerability [4]_.
* Does not support use FPU in First-Level Interrupt Handling (FLIH) [6]_ at
current stage.
@@ -73,7 +76,7 @@
+--------------------------+---------------------------+
| CONFIG_TFM_ENABLE_FP | FP support |
+==========================+===========================+
- | off (default) | FP diasabled |
+ | off (default) | FP disabled |
+--------------------------+---------------------------+
| on | FP enabled |
+--------------------------+---------------------------+
@@ -107,7 +110,8 @@
target, valid for FP hardware ABI type.
FP architecture is processor dependent. For GNUARM compiler, example value
- are: auto, fpv5-d16, fpv5-sp-d16, etc.
+ 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.
@@ -115,6 +119,16 @@
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
+ by Arm Compiler and shall be aligned with ``CONFIG_TFM_FP_ARCH``.
+
+ FP architecture is processor dependent. For armasm and armlink, example value
+ are: SoftVFP, FPv5_D16, etc.
+
+ 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.
*********
Reference
@@ -137,6 +151,8 @@
.. [9] `Armv8-M Architecture Reference Manual <https://developer.arm.com/documentation/ddi0553/latest>`_
+.. [10] `Arm Compiler for Embedded <https://developer.arm.com/Tools%20and%20Software/Arm%20Compiler%20for%20Embedded>`_
+
--------------
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