clang work with imxrt tested with metro rt1011 and rt1060 evk. Don't use startfiles for imxrt

2 files changed, 39 insertions, 22 deletions

diff --git a/hw/bsp/imxrt/family.c b/hw/bsp/imxrt/family.c
index 8ed72aa19..b2e08f9b7 100644
--- a/hw/bsp/imxrt/family.c
+++ b/hw/bsp/imxrt/family.c
@@ -224,3 +224,19 @@ uint32_t board_millis(void) {
   return system_ticks;
 }
 #endif
+
+
+// Implement _start() since we use linker flag '-nostartfiles'.
+// Requires defined __STARTUP_CLEAR_BSS,
+extern int main(void);
+TU_ATTR_UNUSED void _start(void) {
+  // called by startup code
+  main();
+  while (1) {}
+}
+
+#ifdef __clang__
+void	_exit (int __status) {
+  while (1) {}
+}
+#endif
diff --git a/hw/bsp/imxrt/family.cmake b/hw/bsp/imxrt/family.cmake
index 090014754..f4d7378a5 100644
--- a/hw/bsp/imxrt/family.cmake
+++ b/hw/bsp/imxrt/family.cmake
@@ -1,9 +1,5 @@
 include_guard()
 
-if (NOT BOARD)
-  message(FATAL_ERROR "BOARD not specified")
-endif ()
-
 set(SDK_DIR ${TOP}/hw/mcu/nxp/mcux-sdk)
 set(CMSIS_DIR ${TOP}/lib/CMSIS_5)
 
@@ -26,7 +22,21 @@ function(add_board_target BOARD_TARGET)
     return()
   endif ()
 
+  # LD_FILE and STARTUP_FILE can be defined in board.cmake
+  if (NOT DEFINED LD_FILE_${CMAKE_C_COMPILER_ID})
+    set(LD_FILE_GNU ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/${MCU_VARIANT}xxxxx${MCU_CORE}_flexspi_nor.ld)
+    #set(LD_FILE_IAR ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/${MCU_VARIANT}xxxxx_flexspi_nor.ld)
+  endif ()
+  set(LD_FILE_Clang ${LD_FILE_GNU})
+
+  if (NOT DEFINED STARTUP_FILE_${CMAKE_C_COMPILER_ID})
+    set(STARTUP_FILE_GNU ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/startup_${MCU_VARIANT_WITH_CORE}.S)
+    #set(STARTUP_FILE_IAR ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/startup_${MCU_VARIANT_WITH_CORE}.S)
+  endif ()
+  set(STARTUP_FILE_Clang ${STARTUP_FILE_GNU})
+
   add_library(${BOARD_TARGET} STATIC
+    ${STARTUP_FILE_${CMAKE_C_COMPILER_ID}}
     ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/boards/${BOARD}/board/clock_config.c
     ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/boards/${BOARD}/board/pin_mux.c
     ${SDK_DIR}/drivers/common/fsl_common.c
@@ -52,6 +62,7 @@ function(add_board_target BOARD_TARGET)
     __ARMFPV5__=0
     XIP_EXTERNAL_FLASH=1
     XIP_BOOT_HEADER_ENABLE=1
+    __STARTUP_CLEAR_BSS
     )
   target_include_directories(${BOARD_TARGET} PUBLIC
     ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/boards/${BOARD}
@@ -68,31 +79,21 @@ function(add_board_target BOARD_TARGET)
 
   update_board(${BOARD_TARGET})
 
-  # LD_FILE and STARTUP_FILE can be defined in board.cmake
-  if (NOT DEFINED LD_FILE_${CMAKE_C_COMPILER_ID})
-    set(LD_FILE_GNU ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/${MCU_VARIANT}xxxxx${MCU_CORE}_flexspi_nor.ld)
-    #set(LD_FILE_IAR ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/${MCU_VARIANT}xxxxx_flexspi_nor.ld)
-  endif ()
-
-  if (NOT DEFINED STARTUP_FILE_${CMAKE_C_COMPILER_ID})
-    set(STARTUP_FILE_GNU ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/startup_${MCU_VARIANT_WITH_CORE}.S)
-    #set(STARTUP_FILE_IAR ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/startup_${MCU_VARIANT_WITH_CORE}.S)
-  endif ()
-
-  target_sources(${BOARD_TARGET} PUBLIC
-    ${STARTUP_FILE_${CMAKE_C_COMPILER_ID}}
-    )
-
   if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
     target_link_options(${BOARD_TARGET} PUBLIC
       "LINKER:--script=${LD_FILE_GNU}"
-      # nanolib
-      --specs=nosys.specs
-      --specs=nano.specs
+      -nostartfiles
+      --specs=nosys.specs --specs=nano.specs
       # force linker to look for these symbols
       -Wl,-uimage_vector_table
       -Wl,-ug_boot_data
       )
+  elseif (CMAKE_C_COMPILER_ID STREQUAL "Clang")
+    target_link_options(${BOARD_TARGET} PUBLIC
+      "LINKER:--script=${LD_FILE_GNU}"
+      -Wl,-uimage_vector_table
+      -Wl,-ug_boot_data
+      )
   elseif (CMAKE_C_COMPILER_ID STREQUAL "IAR")
     target_link_options(${BOARD_TARGET} PUBLIC
       "LINKER:--config=${LD_FILE_IAR}"