diff --git a/libraries/mbed/targets/cmsis/TOOLCHAIN_IAR/cmain.s b/libraries/mbed/targets/cmsis/TOOLCHAIN_IAR/cmain.s
new file mode 100644
index 0000000000..7395d3fa57
--- /dev/null
+++ b/libraries/mbed/targets/cmsis/TOOLCHAIN_IAR/cmain.s
@@ -0,0 +1,81 @@
+/**************************************************
+ *
+ * Part two of the system initialization code, contains C-level
+ * initialization, thumb-2 only variant.
+ *
+ * Copyright 2006 IAR Systems. All rights reserved.
+ *
+ * $Revision: 59783 $
+ *
+ **************************************************/
+
+
+; --------------------------------------------------
+; Module ?cmain, C-level initialization.
+;
+
+
+ SECTION SHT$$PREINIT_ARRAY:CONST:NOROOT(2)
+ SECTION SHT$$INIT_ARRAY:CONST:NOROOT(2)
+
+ SECTION .text:CODE:NOROOT(2)
+
+ PUBLIC __cmain
+ ;; Keep ?main for legacy reasons, it is accessed in countless instances of cstartup.s around the world...
+ PUBLIC ?main
+ EXTWEAK __iar_data_init3
+ EXTWEAK __iar_argc_argv
+ EXTERN __low_level_init
+ EXTERN __call_ctors
+ EXTERN main
+ EXTERN exit
+ EXTERN __iar_dynamic_initialization
+ EXTERN mbed_sdk_init
+ EXTERN SystemInit
+
+ THUMB
+__cmain:
+?main:
+
+; Initialize segments.
+; __segment_init and __low_level_init are assumed to use the same
+; instruction set and to be reachable by BL from the ICODE segment
+; (it is safest to link them in segment ICODE).
+
+ FUNCALL __cmain, __low_level_init
+ bl __low_level_init
+ cmp r0,#0
+ beq ?l1
+ FUNCALL __cmain, __iar_data_init3
+ bl __iar_data_init3
+ MOVS r0,#0 ; No parameters
+ FUNCALL __cmain, mbed_sdk_init
+ BL mbed_sdk_init
+ MOVS r0,#0 ; No parameters
+ FUNCALL __cmain, __iar_dynamic_initialization
+ BL __iar_dynamic_initialization ; C++ dynamic initialization
+
+?l1:
+ REQUIRE ?l3
+
+ SECTION .text:CODE:NOROOT(2)
+
+ PUBLIC _main
+ PUBLIC _call_main
+ THUMB
+
+__iar_init$$done: ; Copy initialization is done
+
+?l3:
+_call_main:
+ MOVS r0,#0 ; No parameters
+ FUNCALL __cmain, __iar_argc_argv
+ BL __iar_argc_argv ; Maybe setup command line
+
+ FUNCALL __cmain, main
+ BL main
+_main:
+ FUNCALL __cmain, exit
+ BL exit
+
+ END
diff --git a/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h b/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h
index d3abb20148..c36f806d73 100755
--- a/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h
+++ b/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h
@@ -436,21 +436,34 @@ __attribute__((naked)) void software_init_hook (void) {
#elif defined (__ICCARM__)
+extern void* __vector_table;
extern int __low_level_init(void);
extern void __iar_data_init3(void);
+extern __weak void __iar_init_core( void );
+extern __weak void __iar_init_vfp( void );
+extern void __iar_dynamic_initialization(void);
+extern void mbed_sdk_init(void);
extern void exit(int arg);
-__noreturn __stackless void __cmain(void) {
+#pragma required=__vector_table
+void __iar_program_start( void )
+{
+ __iar_init_core();
+ __iar_init_vfp();
+
int a;
if (__low_level_init() != 0) {
__iar_data_init3();
- }
+ mbed_sdk_init();
+ __iar_dynamic_initialization();
+ }
osKernelInitialize();
set_main_stack();
osThreadCreate(&os_thread_def_main, NULL);
a = osKernelStart();
- exit(a);
+ exit(a);
+
}
#endif
diff --git a/workspace_tools/export/iar_arch_pro.ewp.tmpl b/workspace_tools/export/iar_arch_pro.ewp.tmpl
index 6eb8e14536..96900d1d69 100644
--- a/workspace_tools/export/iar_arch_pro.ewp.tmpl
+++ b/workspace_tools/export/iar_arch_pro.ewp.tmpl
@@ -722,11 +722,11 @@