From 059952c8e185994c4cb166ce8f6b07c68f2028f3 Mon Sep 17 00:00:00 2001
From: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
Date: Fri, 29 Jun 2018 11:41:28 +0200
Subject: [PATCH] arch: arm: update compile options for DSP

This commit updates the compile options in cmake to distinguish
between ARMv8-M Mainline MCUs with or withouth the optional DSP
extension. A new Kconfig option: ARMV8_M_DSP, is introduced, to
signify the use of an ARMv8-M MCU with DSP support.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
---
 arch/arm/CMakeLists.txt        | 13 +++++++------
 arch/arm/core/cortex_m/Kconfig |  8 ++++++++
 cmake/gcc-m-cpu.cmake          |  6 +++++-
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/arch/arm/CMakeLists.txt b/arch/arm/CMakeLists.txt
index ed20e40320c..8fc468bfece 100644
--- a/arch/arm/CMakeLists.txt
+++ b/arch/arm/CMakeLists.txt
@@ -1,11 +1,12 @@
 zephyr_cc_option_ifdef(CONFIG_LTO -flto)
 
-set(ARCH_FOR_cortex-m0     armv6-m     )
-set(ARCH_FOR_cortex-m0plus armv6-m     )
-set(ARCH_FOR_cortex-m3     armv7-m     )
-set(ARCH_FOR_cortex-m4     armv7e-m    )
-set(ARCH_FOR_cortex-m23    armv8-m.base)
-set(ARCH_FOR_cortex-m33    armv8-m.main)
+set(ARCH_FOR_cortex-m0        armv6-m         )
+set(ARCH_FOR_cortex-m0plus    armv6-m         )
+set(ARCH_FOR_cortex-m3        armv7-m         )
+set(ARCH_FOR_cortex-m4        armv7e-m        )
+set(ARCH_FOR_cortex-m23       armv8-m.base    )
+set(ARCH_FOR_cortex-m33       armv8-m.main+dsp)
+set(ARCH_FOR_cortex-m33+nodsp armv8-m.main    )
 
 set_property(GLOBAL PROPERTY E_KERNEL_ENTRY  -e${CONFIG_KERNEL_ENTRY})
 
diff --git a/arch/arm/core/cortex_m/Kconfig b/arch/arm/core/cortex_m/Kconfig
index c4075db4687..2e06a14d298 100644
--- a/arch/arm/core/cortex_m/Kconfig
+++ b/arch/arm/core/cortex_m/Kconfig
@@ -252,6 +252,14 @@ config ARMV7_M_ARMV8_M_FP
 	  implementation, or the use of an ARMv8-M processor
 	  implementation supporting the Floating-Point Extension.
 
+config ARMV8_M_DSP
+	bool
+	# Omit prompt to signify "hidden" option
+	depends on ARMV8_M_MAINLINE
+	help
+	  This option signifies the use of an ARMv8-M processor
+	  implementation supporting the DSP Extension.
+
 menu "ARM Cortex-M options"
 	depends on CPU_CORTEX_M
 
diff --git a/cmake/gcc-m-cpu.cmake b/cmake/gcc-m-cpu.cmake
index 270ea4d83f9..cabd8dbd2c0 100644
--- a/cmake/gcc-m-cpu.cmake
+++ b/cmake/gcc-m-cpu.cmake
@@ -15,7 +15,11 @@ if("${ARCH}" STREQUAL "arm")
   elseif(CONFIG_CPU_CORTEX_M23)
     set(GCC_M_CPU cortex-m23)
   elseif(CONFIG_CPU_CORTEX_M33)
-    set(GCC_M_CPU cortex-m33)
+    if    (CONFIG_ARMV8_M_DSP)
+      set(GCC_M_CPU cortex-m33)
+    else()
+      set(GCC_M_CPU cortex-m33+nodsp)
+    endif()
   else()
     message(FATAL_ERROR "Expected CONFIG_CPU_CORTEX_x to be defined")
   endif()