[bsp][stm32f746-disco] Add support of IAR tool chain

1. Add IAR project template and link scripts. Add missing CXX configuration for IAR tool chain in rtconfg.py.
2. Modify all link scripts, Using ITCM interface.(Changing flash start address from 0x0800_0000 to 0x0020_0000).

bsp/stm32f7-disco/rtconfig.py

@@ -19,10 +19,8 @@ elif CROSS_TOOL == 'keil':
     PLATFORM 	= 'armcc'
     EXEC_PATH 	= r'C:/Keil_v5'
 elif CROSS_TOOL == 'iar':
-    print '================ERROR============================'
-    print 'Not support iar yet!'
-    print '================================================='
-    exit(0)
+	PLATFORM 	= 'iar'
+	IAR_PATH 	= 'C:/Program Files (x86)/IAR Systems/Embedded Workbench 7.2'
 
 if os.getenv('RTT_EXEC_PATH'):
     EXEC_PATH = os.getenv('RTT_EXEC_PATH')
@@ -99,6 +97,7 @@ elif PLATFORM == 'armcc':
 elif PLATFORM == 'iar':
     # toolchains
     CC = 'iccarm'
+    CXX = 'iccarm'
     AS = 'iasmarm'
     AR = 'iarchive'
     LINK = 'ilinkarm'
@@ -123,18 +122,23 @@ elif PLATFORM == 'iar':
     CFLAGS += ' --dlib_config "' + IAR_PATH + '/arm/INC/c/DLib_Config_Normal.h"'    
     CFLAGS += ' -Ol'    
     CFLAGS += ' --use_c++_inline'
-        
+    CFLAGS += ' --silent'
+    
     AFLAGS = ''
     AFLAGS += ' -s+' 
     AFLAGS += ' -w+' 
     AFLAGS += ' -r' 
     AFLAGS += ' --cpu Cortex-M7' 
     AFLAGS += ' --fpu None' 
-
+    AFLAGS += ' -S' 
+    
     LFLAGS = ' --config rtthread-stm32f7xx.icf'
     LFLAGS += ' --redirect _Printf=_PrintfTiny' 
     LFLAGS += ' --redirect _Scanf=_ScanfSmall' 
     LFLAGS += ' --entry __iar_program_start'    
+    LFLAGS += ' --silent'
+
+    CXXFLAGS = CFLAGS
 
     EXEC_PATH = IAR_PATH + '/arm/bin/'
     POST_ACTION = ''

bsp/stm32f7-disco/rtthread-stm32f7xx.icf

@@ -0,0 +1,33 @@
+/*###ICF### Section handled by ICF editor, don't touch! ****/
+/*-Editor annotation file-*/
+/* IcfEditorFile="$TOOLKIT_DIR$\config\ide\IcfEditor\cortex_v1_0.xml" */
+/*-Specials-*/
+define symbol __ICFEDIT_intvec_start__ = 0x00200000;
+/*-Memory Regions-*/
+define symbol __ICFEDIT_region_ROM_start__    = 0x00200000;
+define symbol __ICFEDIT_region_ROM_end__      = 0x002FFFFF;
+define symbol __ICFEDIT_region_RAM_start__    = 0x20010000;
+define symbol __ICFEDIT_region_RAM_end__      = 0x2003FFFF;
+/*-Sizes-*/
+define symbol __ICFEDIT_size_cstack__ = 0x400;
+define symbol __ICFEDIT_size_heap__   = 0x200;
+/**** End of ICF editor section. ###ICF###*/
+
+
+define memory mem with size = 4G;
+define region ROM_region      = mem:[from __ICFEDIT_region_ROM_start__   to __ICFEDIT_region_ROM_end__];
+define region RAM_region      = mem:[from __ICFEDIT_region_RAM_start__   to __ICFEDIT_region_RAM_end__];
+
+define block CSTACK    with alignment = 8, size = __ICFEDIT_size_cstack__   { };
+define block HEAP      with alignment = 8, size = __ICFEDIT_size_heap__     { };
+
+initialize by copy { readwrite };
+do not initialize  { section .noinit };
+
+place at address mem:__ICFEDIT_intvec_start__ { readonly section .intvec };
+
+place in ROM_region   { readonly };
+place in RAM_region   { readwrite, block CSTACK, block HEAP };
+keep { section FSymTab };
+keep { section VSymTab };
+keep { section .rti_fn* };

bsp/stm32f7-disco/rtthread-stm32f7xx.ld

@@ -6,7 +6,7 @@
 /* Program Entry, set to mark it as "used" and avoid gc */
 MEMORY
 {
-    CODE (rx) : ORIGIN = 0x08000000, LENGTH = 1024k /* 1024KB flash */
+    CODE (rx) : ORIGIN = 0x00200000, LENGTH = 1024k /* 1024KB flash */
     DATA (rw) : ORIGIN = 0x20010000, LENGTH =  256k /* 256K sram */
 }
 ENTRY(Reset_Handler)

bsp/stm32f7-disco/rtthread-stm32f7xx.sct

@@ -2,8 +2,8 @@
 ; *** Scatter-Loading Description File generated by uVision ***
 ; *************************************************************
 
-LR_IROM1 0x08000000 0x00100000  {    ; load region size_region
-  ER_IROM1 0x08000000 0x00100000  {  ; load address = execution address
+LR_IROM1 0x00200000 0x00100000  {    ; load region size_region
+  ER_IROM1 0x00200000 0x00100000  {  ; load address = execution address
    *.o (RESET, +First)
    *(InRoot$$Sections)
    .ANY (+RO)