diff --git a/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_ARM_MICRO/startup_efm32zg.s b/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_ARM_MICRO/startup_efm32zg.s
index ede95180f5..8e32b53a73 100644
--- a/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_ARM_MICRO/startup_efm32zg.s
+++ b/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_ARM_MICRO/startup_efm32zg.s
@@ -29,7 +29,7 @@
 ;   <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>
 ; </h>
 
-Stack_Size      EQU     0x00000400
+Stack_Size      EQU     0x00000200
 
                 AREA    STACK, NOINIT, READWRITE, ALIGN=3
 Stack_Mem       SPACE   Stack_Size
diff --git a/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_GCC_ARM/startup_efm32zg.S b/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_GCC_ARM/startup_efm32zg.S
index 2ae76f121c..466de1d800 100644
--- a/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_GCC_ARM/startup_efm32zg.S
+++ b/libraries/mbed/targets/cmsis/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/TOOLCHAIN_GCC_ARM/startup_efm32zg.S
@@ -37,7 +37,7 @@
 #ifdef __STACK_SIZE
     .equ    Stack_Size, __STACK_SIZE
 #else
-    .equ    Stack_Size, 0x400
+    .equ    Stack_Size, 0x200
 #endif
     .globl    __StackTop
     .globl    __StackLimit
diff --git a/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG_STK3400/device.h b/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG_STK3400/device.h
index 0ef7e6deb3..d1873076f9 100644
--- a/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG_STK3400/device.h
+++ b/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32HG_STK3400/device.h
@@ -50,6 +50,11 @@
 
 #define DEVICE_LOWPOWERTIMER    1
 
+// Redefine OPEN_MAX from sys_limits.h to save on RAM.
+// Effect: maximum amount of file handlers = OPEN_MAX
+// This is not going to have an impact, since this is a RAM-limited part anyway.
+#define OPEN_MAX                24
+
 #include "objects.h"
 #include "Modules.h"
 #include "device_peripherals.h"
diff --git a/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/device.h b/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/device.h
index 0ef7e6deb3..d7b54e2aaf 100644
--- a/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/device.h
+++ b/libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32ZG_STK3200/device.h
@@ -50,6 +50,11 @@
 
 #define DEVICE_LOWPOWERTIMER    1
 
+// Redefine OPEN_MAX from sys_limits.h to save on RAM.
+// Effect: maximum amount of file handlers = OPEN_MAX
+// This is not going to have an impact, since this is a RAM-limited part anyway.
+#define OPEN_MAX                8
+
 #include "objects.h"
 #include "Modules.h"
 #include "device_peripherals.h"
diff --git a/workspace_tools/export/gcc_arm_efm32gg_stk3700.tmpl b/workspace_tools/export/gcc_arm_efm32gg_stk3700.tmpl
index d248ebfc81..5a3920aabe 100644
--- a/workspace_tools/export/gcc_arm_efm32gg_stk3700.tmpl
+++ b/workspace_tools/export/gcc_arm_efm32gg_stk3700.tmpl
@@ -23,7 +23,7 @@ OBJDUMP = $(GCC_BIN)arm-none-eabi-objdump
 SIZE 	= $(GCC_BIN)arm-none-eabi-size
 
 CPU = -mcpu=cortex-m3 -mthumb
-CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections
+CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections -fno-common -fomit-frame-pointer
 CC_FLAGS += -MMD -MP
 
 ifeq ($(DEBUG), 1)
@@ -53,7 +53,7 @@ clean:
 	$(CC)  $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu99   $(INCLUDE_PATHS) -o $@ $<
 
 .cpp.o:
-	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
+	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -fno-rtti -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
 
 
 $(OBJ_FOLDER)$(PROJECT).axf: $(OBJECTS) $(SYS_OBJECTS)
diff --git a/workspace_tools/export/gcc_arm_efm32hg_stk3400.tmpl b/workspace_tools/export/gcc_arm_efm32hg_stk3400.tmpl
index 65d85dfd8a..b45dc6469e 100644
--- a/workspace_tools/export/gcc_arm_efm32hg_stk3400.tmpl
+++ b/workspace_tools/export/gcc_arm_efm32hg_stk3400.tmpl
@@ -23,7 +23,7 @@ OBJDUMP = $(GCC_BIN)arm-none-eabi-objdump
 SIZE 	= $(GCC_BIN)arm-none-eabi-size
 
 CPU = -mcpu=cortex-m0plus -mthumb
-CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections
+CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections -fno-common -fomit-frame-pointer
 CC_FLAGS += -MMD -MP
 
 ifeq ($(DEBUG), 1)
@@ -53,7 +53,7 @@ clean:
 	$(CC)  $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu99   $(INCLUDE_PATHS) -o $@ $<
 
 .cpp.o:
-	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
+	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -fno-rtti -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
 
 
 $(OBJ_FOLDER)$(PROJECT).axf: $(OBJECTS) $(SYS_OBJECTS)
diff --git a/workspace_tools/export/gcc_arm_efm32lg_stk3600.tmpl b/workspace_tools/export/gcc_arm_efm32lg_stk3600.tmpl
index d248ebfc81..5a3920aabe 100644
--- a/workspace_tools/export/gcc_arm_efm32lg_stk3600.tmpl
+++ b/workspace_tools/export/gcc_arm_efm32lg_stk3600.tmpl
@@ -23,7 +23,7 @@ OBJDUMP = $(GCC_BIN)arm-none-eabi-objdump
 SIZE 	= $(GCC_BIN)arm-none-eabi-size
 
 CPU = -mcpu=cortex-m3 -mthumb
-CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections
+CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections -fno-common -fomit-frame-pointer
 CC_FLAGS += -MMD -MP
 
 ifeq ($(DEBUG), 1)
@@ -53,7 +53,7 @@ clean:
 	$(CC)  $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu99   $(INCLUDE_PATHS) -o $@ $<
 
 .cpp.o:
-	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
+	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -fno-rtti -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
 
 
 $(OBJ_FOLDER)$(PROJECT).axf: $(OBJECTS) $(SYS_OBJECTS)
diff --git a/workspace_tools/export/gcc_arm_efm32wg_stk3800.tmpl b/workspace_tools/export/gcc_arm_efm32wg_stk3800.tmpl
index d248ebfc81..5a3920aabe 100644
--- a/workspace_tools/export/gcc_arm_efm32wg_stk3800.tmpl
+++ b/workspace_tools/export/gcc_arm_efm32wg_stk3800.tmpl
@@ -23,7 +23,7 @@ OBJDUMP = $(GCC_BIN)arm-none-eabi-objdump
 SIZE 	= $(GCC_BIN)arm-none-eabi-size
 
 CPU = -mcpu=cortex-m3 -mthumb
-CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections
+CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections -fno-common -fomit-frame-pointer
 CC_FLAGS += -MMD -MP
 
 ifeq ($(DEBUG), 1)
@@ -53,7 +53,7 @@ clean:
 	$(CC)  $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu99   $(INCLUDE_PATHS) -o $@ $<
 
 .cpp.o:
-	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
+	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -fno-rtti -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
 
 
 $(OBJ_FOLDER)$(PROJECT).axf: $(OBJECTS) $(SYS_OBJECTS)
diff --git a/workspace_tools/export/gcc_arm_efm32zg_stk3200.tmpl b/workspace_tools/export/gcc_arm_efm32zg_stk3200.tmpl
index 65d85dfd8a..b45dc6469e 100644
--- a/workspace_tools/export/gcc_arm_efm32zg_stk3200.tmpl
+++ b/workspace_tools/export/gcc_arm_efm32zg_stk3200.tmpl
@@ -23,7 +23,7 @@ OBJDUMP = $(GCC_BIN)arm-none-eabi-objdump
 SIZE 	= $(GCC_BIN)arm-none-eabi-size
 
 CPU = -mcpu=cortex-m0plus -mthumb
-CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections
+CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -fno-exceptions -ffunction-sections -fdata-sections -fno-common -fomit-frame-pointer
 CC_FLAGS += -MMD -MP
 
 ifeq ($(DEBUG), 1)
@@ -53,7 +53,7 @@ clean:
 	$(CC)  $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu99   $(INCLUDE_PATHS) -o $@ $<
 
 .cpp.o:
-	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
+	$(CPP) $(CC_FLAGS) $(CC_SYMBOLS) -fno-rtti -std=gnu++98 $(INCLUDE_PATHS) -o $@ $<
 
 
 $(OBJ_FOLDER)$(PROJECT).axf: $(OBJECTS) $(SYS_OBJECTS)
diff --git a/workspace_tools/export/simplicityv3_slsproj.tmpl b/workspace_tools/export/simplicityv3_slsproj.tmpl
index 00535b5fa3..ac4d35519f 100644
--- a/workspace_tools/export/simplicityv3_slsproj.tmpl
+++ b/workspace_tools/export/simplicityv3_slsproj.tmpl
@@ -62,8 +62,10 @@
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.c.linker.base" optionId="gnu.c.link.option.ldflags" value="-Wl,--wrap=main"/>
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.linker.base" optionId="gnu.cpp.link.option.flags" value="-Wl,--wrap=main"/>
 {# For debug build, don't apply optimizations #}
+    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.c.compiler.base" optionId="gnu.c.compiler.option.optimization.level" value="gnu.c.optimization.level.none"/>
+    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.c.compiler.base" optionId="gnu.c.compiler.option.misc.other" value="-c -fmessage-length=0 -fno-rtti -fno-exceptions -fno-common -fomit-frame-pointer"/>
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="gnu.cpp.compiler.option.optimization.level" value="gnu.cpp.compiler.optimization.level.none"/>
-    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="gnu.cpp.compiler.option.other.other" value="-c -fmessage-length=0 "/>
+    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="gnu.cpp.compiler.option.other.other" value="-c -fmessage-length=0 -fno-rtti -fno-exceptions -fno-common -fomit-frame-pointer"/>
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.misc.dialect" value="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.misc.dialect.default"/>
   </configuration>
   <configuration name="com.silabs.ide.si32.gcc.release#com.silabs.ide.si32.gcc:4.8.3.20131129" label="GNU ARM v4.8.3 - Release" stockConfigCompatibility="com.silabs.ide.toolchain.core.release">
@@ -105,8 +107,10 @@
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.c.linker.base" optionId="gnu.c.link.option.ldflags" value="-Wl,--wrap=main"/>
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.linker.base" optionId="gnu.cpp.link.option.flags" value="-Wl,--wrap=main"/>
 {# Use optimize for size on release build #}
+    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.c.compiler.base" optionId="gnu.c.compiler.option.optimization.level" value="gnu.c.optimization.level.size"/>
+    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.c.compiler.base" optionId="gnu.c.compiler.option.misc.other" value="-c -fmessage-length=0 -fno-rtti -fno-exceptions -fno-common -fomit-frame-pointer"/>
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="gnu.cpp.compiler.option.optimization.level" value="gnu.cpp.compiler.optimization.level.size"/>
-    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="gnu.cpp.compiler.option.other.other" value="-c -fmessage-length=0 "/>
+    <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="gnu.cpp.compiler.option.other.other" value="-c -fmessage-length=0 -fno-rtti -fno-exceptions -fno-common -fomit-frame-pointer"/>
     <toolOption toolId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.base" optionId="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.misc.dialect" value="com.silabs.ide.si32.gcc.cdt.managedbuild.tool.gnu.cpp.compiler.misc.dialect.default"/>
   </configuration>
 </project>