cmake: Fix arm compiler build failures

Update arm compiler flags which were causing build failures.

Remove `-MMD` flag as it is not recognised by the Arm compiler.

There are no common flags between compiler, assembler and linker. The
compiler expects `-mcpu` whereas assembler and linker expects `--cpu`.

The `COMMON_FLAGS` in `cmake/toolchains/ARM.cmake` are not recognised by
assembler and linker.

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>

Author: urutva

cmake/cores/Cortex-M4F.cmake

@@ -28,7 +28,9 @@ set(CMAKE_CXX_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} \
 elseif(MBED_TOOLCHAIN STREQUAL "ARM")
 
 set(ARM_FLAGS " \
-    --cpu=Cortex-M4.fp.sp \
+    -mcpu=cortex-m4 \
+    -mfpu=fpv4-sp-d16 \
+    -mfloat-abi=hard \
 ")
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} \
@@ -38,10 +40,10 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} \
     ${ARM_FLAGS} \
 ")
 set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} \
-    ${ARM_FLAGS} \
+    --cpu=Cortex-M4 \
 ")
 set(CMAKE_CXX_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} \
-    ${ARM_FLAGS} \
+    --cpu=Cortex-M4 \
 ")
 
 endif()

cmake/toolchains/ARM.cmake

@@ -16,7 +16,6 @@ set(COMMON_FLAGS " \
     -Wno-deprecated-register \
     -fdata-sections \
     -fno-exceptions \
-    -MMD \
     -fshort-enums \
     -fshort-wchar \
 ")
@@ -27,10 +26,8 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} \
     ${COMMON_FLAGS} \
 ")
 set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} \
-    ${COMMON_FLAGS} \
-")
-set(CMAKE_CXX_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} \
-    ${COMMON_FLAGS} \
+    --cpreproc \
+    --cpreproc_opts=--target=arm-arm-none-eabi,-mcpu=cortex-m4,-D,__FPU_PRESENT,-D,MBED_CONF_PLATFORM_CRASH_CAPTURE_ENABLED \
 ")
 
 add_definitions(