clang build board test with h743

examples/build_system/cmake/cpu/cortex-m7.cmake

@@ -5,7 +5,6 @@ if (TOOLCHAIN STREQUAL "gcc")
     -mfloat-abi=hard
     -mfpu=fpv5-d16
     )
-
   set(FREERTOS_PORT GCC_ARM_CM7 CACHE INTERNAL "")
 
 elseif (TOOLCHAIN STREQUAL "iar")
@@ -13,7 +12,15 @@ elseif (TOOLCHAIN STREQUAL "iar")
     --cpu cortex-m7
     --fpu VFPv5_D16
     )
-
   set(FREERTOS_PORT IAR_ARM_CM7 CACHE INTERNAL "")
 
+elseif (TOOLCHAIN STREQUAL "clang")
+  set(TOOLCHAIN_COMMON_FLAGS
+    --target=arm-none-eabi
+    -mcpu=cortex-m7
+    -mfloat-abi=hard
+    -mfpu=fpv5-d16
+    )
+  set(FREERTOS_PORT GCC_ARM_CM7 CACHE INTERNAL "")
+
 endif ()

examples/build_system/cmake/toolchain/arm_clang.cmake

@@ -0,0 +1,21 @@
+if (NOT DEFINED CMAKE_C_COMPILER)
+  set(CMAKE_C_COMPILER "clang")
+endif ()
+
+if (NOT DEFINED CMAKE_CXX_COMPILER)
+  set(CMAKE_CXX_COMPILER "clang++")
+endif ()
+
+set(CMAKE_ASM_COMPILER ${CMAKE_C_COMPILER})
+set(CMAKE_SIZE "llvm-size" CACHE FILEPATH "")
+set(CMAKE_OBJCOPY "llvm-objcopy" CACHE FILEPATH "")
+set(CMAKE_OBJDUMP "llvm-objdump" CACHE FILEPATH "")
+
+include(${CMAKE_CURRENT_LIST_DIR}/common.cmake)
+
+get_property(IS_IN_TRY_COMPILE GLOBAL PROPERTY IN_TRY_COMPILE)
+if (IS_IN_TRY_COMPILE)
+  set(CMAKE_C_LINK_FLAGS "${CMAKE_C_LINK_FLAGS} -nostdlib")
+  set(CMAKE_CXX_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} -nostdlib")
+  cmake_print_variables(CMAKE_C_LINK_FLAGS)
+endif ()

examples/build_system/cmake/toolchain/common.cmake

@@ -37,7 +37,16 @@ elseif (TOOLCHAIN STREQUAL "iar")
     --diag_suppress=Li065
     )
 elseif (TOOLCHAIN STREQUAL "clang")
-  message(FATAL_ERROR "Clang not supported")
+  list(APPEND TOOLCHAIN_COMMON_FLAGS
+    -fdata-sections
+    -ffunction-sections
+    -fno-strict-aliasing
+    )
+  list(APPEND TOOLCHAIN_EXE_LINKER_FLAGS
+    -Wl,--print-memory-usage
+    -Wl,--gc-sections
+    -Wl,--cref
+    )
 endif ()
 
 # join the toolchain flags into a single string

hw/bsp/family_support.cmake

@@ -10,13 +10,22 @@ get_filename_component(TOP ${TOP} ABSOLUTE)
 # Toolchain
 # Can be changed via -DTOOLCHAIN=gcc|iar or -DCMAKE_C_COMPILER=
 #-------------------------------------------------------------
+# Detect toolchain based on CMAKE_C_COMPILER
 if (DEFINED CMAKE_C_COMPILER)
   string(FIND ${CMAKE_C_COMPILER} "iccarm" IS_IAR)
+  string(FIND ${CMAKE_C_COMPILER} "clang" IS_CLANG)
+  string(FIND ${CMAKE_C_COMPILER} "gcc" IS_GCC)
+
   if (NOT IS_IAR EQUAL -1)
     set(TOOLCHAIN iar)
+  elseif (NOT IS_CLANG EQUAL -1)
+    set(TOOLCHAIN clang)
+  elseif (NOT IS_GCC EQUAL -1)
+    set(TOOLCHAIN gcc)
   endif ()
 endif ()
 
+# default to gcc
 if (NOT DEFINED TOOLCHAIN)
   set(TOOLCHAIN gcc)
 endif ()

hw/bsp/stm32h7/family.cmake

@@ -29,6 +29,7 @@ function(add_board_target BOARD_TARGET)
   if (NOT TARGET ${BOARD_TARGET})
     # Startup & Linker script
     set(STARTUP_FILE_GNU ${ST_CMSIS}/Source/Templates/gcc/startup_${MCU_VARIANT}.s)
+    set(STARTUP_FILE_Clang ${STARTUP_FILE_GNU})
     set(STARTUP_FILE_IAR ${ST_CMSIS}/Source/Templates/iar/startup_${MCU_VARIANT}.s)
 
     if(NOT DEFINED LD_FILE_IAR)
@@ -72,6 +73,10 @@ function(add_board_target BOARD_TARGET)
       target_link_options(${BOARD_TARGET} PUBLIC
         "LINKER:--config=${LD_FILE_IAR}"
         )
+    elseif (CMAKE_C_COMPILER_ID STREQUAL "Clang")
+      target_link_options(${BOARD_TARGET} PUBLIC
+        "LINKER:--script=${LD_FILE_GNU}"
+        )
     endif ()
   endif ()
 endfunction()