diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_ARM_STD/efm32gg.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_ARM_STD/efm32gg.sct
index ce41a9ad0e..0e4e9274ec 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_ARM_STD/efm32gg.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_ARM_STD/efm32gg.sct
@@ -11,14 +11,23 @@
   #define MBED_APP_SIZE 0x00100000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x200000E0 0x0001FF20  {  ; RW data
+  RW_IRAM1 0x200000E0 0x0001FF20-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  
+  ARM_LIB_STACK (0x200000E0+0x0001FF20) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_GCC_ARM/efm32gg.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_GCC_ARM/efm32gg.ld
index e1c8092a46..d18bab2739 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_GCC_ARM/efm32gg.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_GCC_ARM/efm32gg.ld
@@ -9,12 +9,6 @@
 /* Version 4.2.0 */
 /*                                                                  */
 
-/* With the RTOS in use, this does not affect the main stack size. The size of
- * the stack where main runs is determined via the RTOS. */
-STACK_SIZE = 0x400;
-
-HEAP_SIZE = 0x6000;
-
 #if !defined(MBED_APP_START)
   #define MBED_APP_START 0x00000000
 #endif
@@ -23,6 +17,16 @@ HEAP_SIZE = 0x6000;
   #define MBED_APP_SIZE 1048576
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+/* With the RTOS in use, this does not affect the main stack size. The size of
+ * the stack where main runs is determined via the RTOS. */
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
+HEAP_SIZE = 0x6000;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -220,7 +224,7 @@ SECTIONS
     __end__ = .;
     end = __end__;
     _end = __end__;
-    . += HEAP_SIZE;
+    . = ORIGIN(RAM) + LENGTH(RAM) - STACK_SIZE;
     __HeapLimit = .;
   } > RAM
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_IAR/efm32gg990f1024.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_IAR/efm32gg990f1024.icf
index e57dada035..0865faf2f9 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_IAR/efm32gg990f1024.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG/device/TARGET_1024K/TOOLCHAIN_IAR/efm32gg990f1024.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00100000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x200000DF;
 define symbol __ICFEDIT_region_RAM_start__   = 0x200000E0;
 define symbol __ICFEDIT_region_RAM_end__     = 0x2001FFFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x4000;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x8000;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_ARM_STD/efm32gg11.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_ARM_STD/efm32gg11.sct
index 796307249b..ac1f199c47 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_ARM_STD/efm32gg11.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_ARM_STD/efm32gg11.sct
@@ -11,14 +11,23 @@
   #define MBED_APP_SIZE 0x00200000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x20000158 0x0007FEA8  {  ; RW data
+  RW_IRAM1 0x20000158 0x0007FEA8-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  
+  ARM_LIB_STACK (0x20000158+0x0007FEA8) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_GCC_ARM/efm32gg11.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_GCC_ARM/efm32gg11.ld
index 699f40b12a..588b65e2d0 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_GCC_ARM/efm32gg11.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_GCC_ARM/efm32gg11.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 0x200000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -212,7 +218,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_IAR/efm32gg11b820f2048gl192.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_IAR/efm32gg11b820f2048gl192.icf
index 25d996e133..dd7b1ce337 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_IAR/efm32gg11b820f2048gl192.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32GG11/device/TOOLCHAIN_IAR/efm32gg11b820f2048gl192.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00200000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x20000157;
 define symbol __ICFEDIT_region_RAM_start__   = 0x20000158;
 define symbol __ICFEDIT_region_RAM_end__     = 0x2007FFFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x4000;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x10000;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_GCC_ARM/efm32hg.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_GCC_ARM/efm32hg.ld
index ffca89e369..24fdde536a 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_GCC_ARM/efm32hg.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_GCC_ARM/efm32hg.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 65536
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -213,7 +219,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_IAR/efm32hg322f64.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_IAR/efm32hg322f64.icf
index 22c8439dfe..caa587a1fc 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_IAR/efm32hg322f64.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG/device/TARGET_64K/TOOLCHAIN_IAR/efm32hg322f64.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00010000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x20000097;
 define symbol __ICFEDIT_region_RAM_start__   = 0x20000098;
 define symbol __ICFEDIT_region_RAM_end__     = 0x20001FFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x400;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x800;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32lg.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32lg.sct
index 3f502bbc80..c192c445a2 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32lg.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32lg.sct
@@ -11,14 +11,22 @@
   #define MBED_APP_SIZE 0x00040000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x200000E0 0x00007F20  {  ; RW data
+  RW_IRAM1 0x200000E0 0x00007F20-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  ARM_LIB_STACK (0x200000E0+0x00007F20) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32lg.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32lg.ld
index 3ccec3d81f..38f59ce7cc 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32lg.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32lg.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 262144
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -212,7 +218,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_IAR/efm32lg990f256.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_IAR/efm32lg990f256.icf
index a21c1364c8..6dd58b14c9 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_IAR/efm32lg990f256.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32LG/device/TARGET_256K/TOOLCHAIN_IAR/efm32lg990f256.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00040000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x200000DF;
 define symbol __ICFEDIT_region_RAM_start__   = 0x200000E0;
 define symbol __ICFEDIT_region_RAM_end__     = 0x20007FFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x1000;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x2000;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32pg1b.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32pg1b.sct
index 5019826e41..3c18ce94ab 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32pg1b.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32pg1b.sct
@@ -11,14 +11,22 @@
   #define MBED_APP_SIZE 0x00040000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x200000C8 0x00007F38  {  ; RW data
+  RW_IRAM1 0x200000C8 0x00007F38-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  ARM_LIB_STACK (0x200000C8+0x00007F38) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32pg1b.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32pg1b.ld
index cc78895a91..75987e0ff3 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32pg1b.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32pg1b.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 262144
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -212,7 +218,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_IAR/efm32pg1b200f256.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_IAR/efm32pg1b200f256.icf
index 66e60ebbd6..7e6d3c981a 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_IAR/efm32pg1b200f256.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG/device/TARGET_256K/TOOLCHAIN_IAR/efm32pg1b200f256.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00040000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x200000C7;
 define symbol __ICFEDIT_region_RAM_start__   = 0x200000C8;
 define symbol __ICFEDIT_region_RAM_end__     = 0x20007FFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x1000;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x2000;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_ARM_STD/efr32pg12b.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_ARM_STD/efr32pg12b.sct
index b06400e44d..19e3a95f55 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_ARM_STD/efr32pg12b.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_ARM_STD/efr32pg12b.sct
@@ -11,14 +11,22 @@
   #define MBED_APP_SIZE 0x00100000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x20000110 0x0003FEF0  {  ; RW data
+  RW_IRAM1 0x20000110 0x0003FEF0-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  ARM_LIB_STACK (0x20000110+0x0003FEF0) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_GCC_ARM/efm32pg12b.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_GCC_ARM/efm32pg12b.ld
index 6ddce74288..5be3187ccb 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_GCC_ARM/efm32pg12b.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_GCC_ARM/efm32pg12b.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 1048576
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -212,7 +218,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_IAR/EFM32PG12B500F1024GL125.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_IAR/EFM32PG12B500F1024GL125.icf
index 2a914564f2..c2f4d74faa 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_IAR/EFM32PG12B500F1024GL125.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32PG12/device/TOOLCHAIN_IAR/EFM32PG12B500F1024GL125.icf
@@ -5,6 +5,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00100000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -18,7 +19,7 @@ define symbol __ICFEDIT_region_RAM_end__     = (0x20000000+0x00040000-1);
 
 /*-Sizes-*/
 if ( !isdefinedsymbol( __ICFEDIT_size_cstack__ ) )
-{ define symbol __ICFEDIT_size_cstack__   = 0x1000; }
+{ define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE; }
 
 if ( !isdefinedsymbol( __ICFEDIT_size_heap__ ) )
 { define symbol __ICFEDIT_size_heap__     = 0x4000; }
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32wg.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32wg.sct
index 3f502bbc80..c192c445a2 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32wg.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_ARM_STD/efm32wg.sct
@@ -11,14 +11,22 @@
   #define MBED_APP_SIZE 0x00040000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x200000E0 0x00007F20  {  ; RW data
+  RW_IRAM1 0x200000E0 0x00007F20-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  ARM_LIB_STACK (0x200000E0+0x00007F20) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32wg.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32wg.ld
index 61dd3871f3..7d1ceb1052 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32wg.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_GCC_ARM/efm32wg.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 262144
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -213,7 +219,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_IAR/efm32wg990f256.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_IAR/efm32wg990f256.icf
index a21c1364c8..6dd58b14c9 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_IAR/efm32wg990f256.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/TARGET_256K/TOOLCHAIN_IAR/efm32wg990f256.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00040000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x200000DF;
 define symbol __ICFEDIT_region_RAM_start__   = 0x200000E0;
 define symbol __ICFEDIT_region_RAM_end__     = 0x20007FFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x1000;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x2000;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_GCC_ARM/efm32zg.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_GCC_ARM/efm32zg.ld
index 22568ec19d..f114bb80cb 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_GCC_ARM/efm32zg.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_GCC_ARM/efm32zg.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 32768
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -213,7 +219,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_IAR/efm32zg222f32.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_IAR/efm32zg222f32.icf
index 2ece65a90e..ae582b33f3 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_IAR/efm32zg222f32.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG/device/TARGET_32K/TOOLCHAIN_IAR/efm32zg222f32.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00008000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x2000008F;
 define symbol __ICFEDIT_region_RAM_start__   = 0x20000090;
 define symbol __ICFEDIT_region_RAM_end__     = 0x20000FFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x200;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x400;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_ARM_STD/efr32mg1p.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_ARM_STD/efr32mg1p.sct
index c9854363dd..9d81efe161 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_ARM_STD/efr32mg1p.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_ARM_STD/efr32mg1p.sct
@@ -11,14 +11,22 @@
   #define MBED_APP_SIZE 0x00040000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x200000C8 0x00007B38  {  ; RW data
+  RW_IRAM1 0x200000C8 0x00007B38-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  ARM_LIB_STACK (0x200000C8+0x00007B38) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_GCC_ARM/efr32mg1p.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_GCC_ARM/efr32mg1p.ld
index ad8928f16d..081ed72d8b 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_GCC_ARM/efr32mg1p.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_GCC_ARM/efr32mg1p.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 262144
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -212,7 +218,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_IAR/efr32mg1p232f256mg48.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_IAR/efr32mg1p232f256mg48.icf
index 851459f5e9..ea5153ba17 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_IAR/efr32mg1p232f256mg48.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG1/device/TOOLCHAIN_IAR/efr32mg1p232f256mg48.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00040000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x200000C7;
 define symbol __ICFEDIT_region_RAM_start__   = 0x200000C8;
 define symbol __ICFEDIT_region_RAM_end__     = 0x20007BFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x400;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x1000;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_ARM_STD/efr32mg12p.sct b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_ARM_STD/efr32mg12p.sct
index b06400e44d..19e3a95f55 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_ARM_STD/efr32mg12p.sct
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_ARM_STD/efr32mg12p.sct
@@ -11,14 +11,22 @@
   #define MBED_APP_SIZE 0x00100000
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+  #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+#define Stack_Size MBED_BOOT_STACK_SIZE
+
 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)
   }
-  RW_IRAM1 0x20000110 0x0003FEF0  {  ; RW data
+  RW_IRAM1 0x20000110 0x0003FEF0-Stack_Size  {  ; RW data
    .ANY (+RW +ZI)
   }
+  ARM_LIB_STACK (0x20000110+0x0003FEF0) EMPTY -Stack_Size { ; stack
+  }
 }
 
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_GCC_ARM/efr32mg12p.ld b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_GCC_ARM/efr32mg12p.ld
index 8ab03636c6..2b5adb147b 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_GCC_ARM/efr32mg12p.ld
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_GCC_ARM/efr32mg12p.ld
@@ -17,6 +17,12 @@
   #define MBED_APP_SIZE 1048576
 #endif
 
+#if !defined(MBED_BOOT_STACK_SIZE)
+    #define MBED_BOOT_STACK_SIZE 0x400
+#endif
+
+STACK_SIZE = MBED_BOOT_STACK_SIZE;
+
 MEMORY
 {
   FLASH (rx) : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
@@ -212,7 +218,7 @@ SECTIONS
   /* Set stack top to end of RAM, and stack limit move down by
    * size of stack_dummy section */
   __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-  __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+  __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);
 
   /* Check if data + heap + stack exceeds RAM limit */
diff --git a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_IAR/efr32mg12p332f1024gl125.icf b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_IAR/efr32mg12p332f1024gl125.icf
index fd26aeb572..35d609b9b8 100644
--- a/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_IAR/efr32mg12p332f1024gl125.icf
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFR32MG12/device/TOOLCHAIN_IAR/efr32mg12p332f1024gl125.icf
@@ -4,6 +4,7 @@
 
 if (!isdefinedsymbol(MBED_APP_START)) { define symbol MBED_APP_START = 0x00000000; }
 if (!isdefinedsymbol(MBED_APP_SIZE)) { define symbol MBED_APP_SIZE = 0x00100000; }
+if (!isdefinedsymbol(MBED_BOOT_STACK_SIZE)) { define symbol MBED_BOOT_STACK_SIZE = 0x400; }
 
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = MBED_APP_START;
@@ -15,8 +16,7 @@ define symbol __NVIC_end__                   = 0x2000010F;
 define symbol __ICFEDIT_region_RAM_start__   = 0x20000110;
 define symbol __ICFEDIT_region_RAM_end__     = 0x2003FFFF;
 /*-Sizes-*/
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __ICFEDIT_size_cstack__   = 0x4000;
+define symbol __ICFEDIT_size_cstack__   = MBED_BOOT_STACK_SIZE;
 define symbol __ICFEDIT_size_heap__     = 0x10000;
 /**** End of ICF editor section. ###ICF###*/