diff --git a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_MICRO/stm32f439xx.sct b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_MICRO/stm32f439xx.sct
index 40ba8dfc42..dea098216f 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_MICRO/stm32f439xx.sct
+++ b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_MICRO/stm32f439xx.sct
@@ -1,3 +1,4 @@
+#! armcc -E
 ; Scatter-Loading Description File
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ; Copyright (c) 2015, STMicroelectronics
@@ -27,19 +28,30 @@
 ; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-; 2 MB FLASH (0x200000) + 256 KB SRAM (0x40000)
-LR_IROM1 0x08000000 0x200000  {    ; load region size_region
+#if !defined(MBED_APP_START)
+  #define MBED_APP_START 0x08000000
+#endif
 
-  ER_IROM1 0x08000000 0x200000  {  ; load address = execution address
+#if !defined(MBED_APP_SIZE)
+  #define MBED_APP_SIZE 0x200000
+#endif
+
+; STM32F439xI: 2048 KB FLASH (0x200000) + 256 KB SRAM (0x30000 + 0x10000)
+LR_IROM1 MBED_APP_START MBED_APP_SIZE  {    ; load region size_region
+
+  ER_IROM1 MBED_APP_START MBED_APP_SIZE  {  ; load address = execution address
    *.o (RESET, +First)
    *(InRoot$$Sections)
    .ANY (+RO)
   }
 
-  ; Total: 107 vectors = 428 bytes (0x1AC) to be reserved in RAM
-  RW_IRAM1 (0x20000000+0x1AC) (0x20000-0x1AC)  {  ; RW data
+  ; Total: 107 vectors = 428 bytes (0x1AC) to be used
+  ; should match ER_IROM1::RESET/4 and cmsis_nvic.h::NVIC_NUM_VECTORS
+  RW_IRAM1 (0x20000000 + (107*4)) (0x30000 - (107*4))  {  ; RW data
    .ANY (+RW +ZI)
   }
-
+  RW_IRAM2 (0x10000000) 0x10000 { 
+   .ANY (+RW +ZI) 
+  }
 }
 
diff --git a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_STD/stm32f439xx.sct b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_STD/stm32f439xx.sct
index 646d1493bf..b114905027 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_STD/stm32f439xx.sct
+++ b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_ARM_STD/stm32f439xx.sct
@@ -1,3 +1,4 @@
+#! armcc -E
 ; Scatter-Loading Description File
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ; Copyright (c) 2015, STMicroelectronics
@@ -27,10 +28,18 @@
 ; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-; 2 MB FLASH (0x200000) + 192 KB SRAM (0x30000)
-LR_IROM1 0x08000000 0x200000  {    ; load region size_region
+#if !defined(MBED_APP_START)
+  #define MBED_APP_START 0x08000000
+#endif
 
-  ER_IROM1 0x08000000 0x200000  {  ; load address = execution address
+#if !defined(MBED_APP_SIZE)
+  #define MBED_APP_SIZE 0x200000
+#endif
+
+; 2 MB FLASH (0x200000) + 256 KB SRAM (0x30000 + 0x10000)
+LR_IROM1 MBED_APP_START MBED_APP_SIZE  {    ; load region size_region
+
+  ER_IROM1 MBED_APP_START MBED_APP_SIZE  {  ; load address = execution address
    *.o (RESET, +First)
    *(InRoot$$Sections)
    .ANY (+RO)
@@ -40,6 +49,9 @@ LR_IROM1 0x08000000 0x200000  {    ; load region size_region
   RW_IRAM1 (0x20000000+0x1AC) (0x30000-0x1AC)  {  ; RW data
    .ANY (+RW +ZI)
   }
-
+  
+  RW_IRAM2 (0x10000000) (0x10000)  {  ; RW data
+   .ANY (+RW +ZI)
+  }
 }
 
diff --git a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_GCC_ARM/STM32F439ZI.ld b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_GCC_ARM/STM32F439ZI.ld
index 1ae1add65c..86820f2823 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_GCC_ARM/STM32F439ZI.ld
+++ b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_GCC_ARM/STM32F439ZI.ld
@@ -1,7 +1,15 @@
+#if !defined(MBED_APP_START)
+  #define MBED_APP_START 0x08000000
+#endif
+
+#if !defined(MBED_APP_SIZE)
+  #define MBED_APP_SIZE 2048k
+#endif
+
 /* Linker script to configure memory regions. */
 MEMORY
 { 
-  FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 2048k
+  FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
   CCM (rwx) : ORIGIN = 0x10000000, LENGTH = 64K
   RAM (rwx) : ORIGIN = 0x200001AC, LENGTH = 192k - 0x1AC 
 }
diff --git a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_IAR/stm32f439xx_flash.icf b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_IAR/stm32f439xx_flash.icf
index 156df266be..3b428be87c 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_IAR/stm32f439xx_flash.icf
+++ b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/device/TOOLCHAIN_IAR/stm32f439xx_flash.icf
@@ -1,11 +1,13 @@
 /*###ICF### Section handled by ICF editor, don't touch! ****/
 /*-Editor annotation file-*/
 /* IcfEditorFile="$TOOLKIT_DIR$\config\ide\IcfEditor\cortex_v1_0.xml" */
+if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x08000000; }
+if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x200000; }
 /*-Specials-*/
-define symbol __ICFEDIT_intvec_start__ = 0x08000000;
+define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
 /*-Memory Regions-*/
-define symbol __ICFEDIT_region_ROM_start__    = 0x08000000;
-define symbol __ICFEDIT_region_ROM_end__      = 0x081FFFFF;
+define symbol __ICFEDIT_region_ROM_start__    = MBED_APP_START;
+define symbol __ICFEDIT_region_ROM_end__      = MBED_APP_START + MBED_APP_SIZE - 1;
 define symbol __ICFEDIT_region_NVIC_start__   = 0x20000000;
 define symbol __ICFEDIT_region_NVIC_end__     = 0x200001AF;
 define symbol __ICFEDIT_region_RAM_start__    = 0x200001B0;
@@ -13,7 +15,7 @@ define symbol __ICFEDIT_region_RAM_end__      = 0x2002FFFF;
 define symbol __ICFEDIT_region_CCMRAM_start__ = 0x10000000;
 define symbol __ICFEDIT_region_CCMRAM_end__   = 0x1000FFFF;
 /*-Sizes-*/
-/*Heap 1/3 of ram and stack 1/8*/
+/*Heap 64kB and stack 24kB */
 define symbol __ICFEDIT_size_cstack__ = 0x6000;
 define symbol __ICFEDIT_size_heap__   = 0x10000;
 /**** End of ICF editor section. ###ICF###*/