diff --git a/radio/src/Makefile b/radio/src/Makefile
index 6bbee36a9..47118c158 100644
--- a/radio/src/Makefile
+++ b/radio/src/Makefile
@@ -289,10 +289,6 @@ USB = JOYSTICK
 # NO - normal behaviour, show real channel values
 CHANNELS_MONITOR_INV_HIDE = NO
 
-# Use newlib-nano 
-# Values = NO, YES
-NANO = YES
-
 #------- END BUILD OPTIONS ---------------------------
 
 # Define programs and commands.
@@ -722,12 +718,6 @@ ifeq ($(PCB), TARANIS)
     EXTRABOARDSRC += targets/taranis/usbd_storage_msd.cpp
   endif
   
-  ifeq ($(NANO), YES)
-    # use newlib-nano for linking
-    NEWLIB_NANO_FLAGS = --specs=nano.specs -u _printf_float
-    CPPDEFS += -DNANO
-  endif
-  
   ifneq ($(LUA), NO)
     ifeq ($(LUA), YES)
       CPPDEFS += -DLUA_MODEL_SCRIPTS
@@ -738,7 +728,6 @@ ifeq ($(PCB), TARANIS)
     LUASRC = lua/src/lapi.c lua/src/lcode.c lua/src/lctype.c lua/src/ldebug.c lua/src/ldo.c lua/src/ldump.c lua/src/lfunc.c lua/src/lgc.c lua/src/llex.c lua/src/lmem.c \
            lua/src/lobject.c lua/src/lopcodes.c lua/src/lparser.c lua/src/lstate.c lua/src/lstring.c lua/src/ltable.c lua/src/ltm.c lua/src/lundump.c lua/src/lvm.c lua/src/lzio.c \
            lua/src/lbaselib.c lua/src/linit.c lua/src/lmathlib.c lua/src/loadlib.c lua/src/lauxlib.c lua/src/ltablib.c lua/src/lcorolib.c lua/src/lbitlib.c
-           # lua/src/loslib.c lua/src/lstrlib.c lua/src/liolib.c lua/src/ldblib.c
     SRC += $(LUASRC) 
     LUADEP = lua_exports.cpp
   endif           
@@ -1400,7 +1389,7 @@ OBJS =  $(TMP:.s=.o)
 	@echo
 	@echo $(MSG_COMPILING) $@
 	$(CC) $(ARMCPPFLAGS) $< -o allsrc.o
-	$(CC) $(OBJS) allsrc.o -mcpu=cortex-m3 -mthumb -nostartfiles -lm -T$(LDSCRIPT) -Wl,-Map=$(TARGET).map,--cref,--no-warn-mismatch,--gc-sections $(NEWLIB_NANO_FLAGS) -o $@
+	$(CC) $(OBJS) allsrc.o -mcpu=cortex-m3 -mthumb -nostartfiles -lm -T$(LDSCRIPT) -Wl,-Map=$(TARGET).map,--cref,--no-warn-mismatch,--gc-sections -o $@
 endif
 
 # Target: clean project.
diff --git a/radio/src/gui/view_statistics.cpp b/radio/src/gui/view_statistics.cpp
index 38c206117..67966664c 100644
--- a/radio/src/gui/view_statistics.cpp
+++ b/radio/src/gui/view_statistics.cpp
@@ -215,13 +215,14 @@ void menuStatisticsDebug(uint8_t event)
   lcd_puts(lcdLastPos, MENU_DEBUG_Y_MIXMAX, "ms");
 #endif
 
-#if defined(PCBTARANIS)
+#if 0
   lcd_putsLeft(MENU_DEBUG_Y_STACK, STR_FREESTACKMINB);
   lcd_outdezAtt(MENU_DEBUG_COL1_OFS, MENU_DEBUG_Y_STACK, stack_free(255), UNSIGN|LEFT);
   lcd_puts(lcdLastPos, MENU_DEBUG_Y_STACK, "b");
 #endif
 
 #if defined(PCBTARANIS)
+  lcd_putsLeft(MENU_DEBUG_Y_RTOS, STR_FREESTACKMINB);
   lcd_putsAtt(MENU_DEBUG_COL1_OFS, MENU_DEBUG_Y_RTOS+1, "[Main]", SMLSIZE);
   lcd_outdezAtt(lcdLastPos, MENU_DEBUG_Y_RTOS, stack_free(0), UNSIGN|LEFT);
   lcd_putsAtt(lcdLastPos+2, MENU_DEBUG_Y_RTOS+1, "[Mix]", SMLSIZE);
diff --git a/radio/src/lua.cpp b/radio/src/lua.cpp
index 498d06992..877a44273 100644
--- a/radio/src/lua.cpp
+++ b/radio/src/lua.cpp
@@ -1796,6 +1796,7 @@ void luaDoOneRunStandalone(uint8_t evt)
           TRACE("Script finished with status %d", scriptResult);
           standaloneScript.state = SCRIPT_NOFILE;
           luaState = INTERPRETER_RELOAD_PERMANENT_SCRIPTS;
+          return;
         }
         else if (luaDisplayStatistics) {
           lcd_hline(0, 7*FH-1, lcdLastPos+FW, ERASE);
@@ -1919,22 +1920,24 @@ void luaDoOneRunPermanentScript(uint8_t evt, int i)
 
 void luaDoGc()
 {
-  PROTECT_LUA() {
-    lua_gc(L, LUA_GCSTEP /*LUA_GCCOLLECT*/, 0);  // LUA_GCSTEP is enough
+  if (L) {
+    PROTECT_LUA() {
+      lua_gc(L, LUA_GCSTEP /*LUA_GCCOLLECT*/, 0);  // LUA_GCSTEP is enough
 #if defined(SIMU) || defined(DEBUG)
-    static int lastgc = 0;
-    int gc = luaGetMemUsed();
-    if (gc != lastgc) {
-      lastgc = gc;
-      TRACE("GC Use: %dbytes", gc);
-    }
+      static int lastgc = 0;
+      int gc = luaGetMemUsed();
+      if (gc != lastgc) {
+        lastgc = gc;
+        TRACE("GC Use: %dbytes", gc);
+      }
 #endif
+    }
+    else {
+      // we disable Lua for the rest of the session
+      luaDisable();
+    }
+    UNPROTECT_LUA();
   }
-  else {
-    // we disable Lua for the rest of the session
-    luaDisable();
-  }
-  UNPROTECT_LUA();
 }
 
 void luaTask(uint8_t evt)
diff --git a/radio/src/targets/sky9x/syscalls.c b/radio/src/targets/sky9x/syscalls.c
index f8a1b2e02..98e270f65 100644
--- a/radio/src/targets/sky9x/syscalls.c
+++ b/radio/src/targets/sky9x/syscalls.c
@@ -46,7 +46,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <errno.h>
-#include "debug.h"
 
 /*----------------------------------------------------------------------------
  *        Exported variables
@@ -54,8 +53,10 @@
 
 #undef errno
 extern int errno;
-extern int _end;
-extern int _main_stack_start;
+extern int  _end;
+extern int _estack;
+
+#define RAM_END (unsigned char *)&_estack
 
 /*----------------------------------------------------------------------------
  *        Exported functions
@@ -67,7 +68,7 @@ extern int _getpid ( void ) ;
 unsigned char *heap = (unsigned char *)&_end;
 extern caddr_t _sbrk(int nbytes)
 {
-  if (heap + nbytes < (unsigned char *)&_main_stack_start) {
+  if (heap + nbytes < RAM_END-4096) {
     unsigned char *prev_heap = heap;
     heap += nbytes;
     return (caddr_t) prev_heap;
@@ -141,8 +142,9 @@ extern int _write( int file, char *ptr, int len )
 
 extern void _exit( int status )
 {
-    TRACE( "Exiting with status %d.\n", status ) ;
-
+#if defined(SIMU)
+    printf( "Exiting with status %d.\n", status ) ;
+#endif
     for ( ; ; ) ;
 }
 
diff --git a/radio/src/targets/taranis/STM32F2xx_StdPeriph_Lib_V1.1.0/Libraries/CMSIS/Device/ST/STM32F2xx/Source/Templates/gcc_ride7/startup_stm32f2xx.s b/radio/src/targets/taranis/STM32F2xx_StdPeriph_Lib_V1.1.0/Libraries/CMSIS/Device/ST/STM32F2xx/Source/Templates/gcc_ride7/startup_stm32f2xx.s
index d6f050acc..65757dd85 100644
--- a/radio/src/targets/taranis/STM32F2xx_StdPeriph_Lib_V1.1.0/Libraries/CMSIS/Device/ST/STM32F2xx/Source/Templates/gcc_ride7/startup_stm32f2xx.s
+++ b/radio/src/targets/taranis/STM32F2xx_StdPeriph_Lib_V1.1.0/Libraries/CMSIS/Device/ST/STM32F2xx/Source/Templates/gcc_ride7/startup_stm32f2xx.s
@@ -98,23 +98,8 @@ LoopFillZerobss:
   ldr  r3, = _ebss
   cmp  r2, r3
   bcc  FillZerobss
-
-/*Paint Main Stack */
-  ldr  r2, = _main_stack_start
-PaintMainStack:
-  movs r3, #0x55555555
-  str  r3, [r2], #4
-LoopPaintMainStack:
-  ldr  r3, = _estack
-  cmp  r2, r3
-  bcc  PaintMainStack
-
 /* Call the clock system intitialization function.*/
   bl  SystemInit   
-
-/* Call C++ constructors for static objects */
-  bl  __libc_init_array
-
 /* Call the application's entry point.*/
   bl  main
   bx  lr    
diff --git a/radio/src/targets/taranis/stm32_flash_bl.ld b/radio/src/targets/taranis/stm32_flash_bl.ld
index c8616ea46..4ff28f4db 100644
--- a/radio/src/targets/taranis/stm32_flash_bl.ld
+++ b/radio/src/targets/taranis/stm32_flash_bl.ld
@@ -34,8 +34,6 @@ ENTRY(Reset_Handler)
 
 /* Highest address of the user mode stack */
 _estack = 0x20020000;    /* end of 128K SRAM */
-_main_stack_size = 0x1000;   /*size of main stack*/
-_main_stack_start = _estack - _main_stack_size;
 
 /* Generate a link error if heap and stack don't fit into RAM */
 _Min_Heap_Size = 0;      /* required amount of heap  */
diff --git a/radio/src/targets/taranis/stm32_ramBoot.ld b/radio/src/targets/taranis/stm32_ramBoot.ld
index cd992dd54..c8204c5ec 100644
--- a/radio/src/targets/taranis/stm32_ramBoot.ld
+++ b/radio/src/targets/taranis/stm32_ramBoot.ld
@@ -21,8 +21,6 @@ ENTRY(Reset_Handler)
 
 /* Highest address of the user mode stack */
 _estack = 0x20020000;    /* end of 128K SRAM */
-_main_stack_size = 0x1000;   /*size of main stack*/
-_main_stack_start = _estack - _main_stack_size;
 
 /* Generate a link error if heap and stack don't fit into RAM */
 _Min_Heap_Size = 0;      /* required amount of heap  */
diff --git a/radio/src/tasks_arm.cpp b/radio/src/tasks_arm.cpp
index 852e5ad7d..0c76c3cc4 100755
--- a/radio/src/tasks_arm.cpp
+++ b/radio/src/tasks_arm.cpp
@@ -99,7 +99,7 @@ uint32_t stack_free(uint32_t tid)
       stack = audioStack;
       size = AUDIO_STACK_SIZE;
       break;
-#if defined(PCBTARANIS) && !defined(SIMU)
+#if 0 // defined(PCBTARANIS) && !defined(SIMU)
     case 255:
       // main stack
       stack = (OS_STK *)&_main_stack_start;