diff --git a/cpu/cc2430/8051def.h b/cpu/cc2430/8051def.h
index e8627ddc4..a1fa15e80 100644
--- a/cpu/cc2430/8051def.h
+++ b/cpu/cc2430/8051def.h
@@ -38,6 +38,13 @@
 #define CC_CONF_UNSIGNED_CHAR_BUGS	0
 #define CC_CONF_REGISTER_ARGS		0
 #define CC_CONF_FUNCTION_POINTER_KEYWORD __reentrant
+#define CC_CONF_NON_BANKED_OPTIMIZATION 1
+
+#if (defined(__SDCC_mcs51) || defined(SDCC_mcs51)) && CC_CONF_NON_BANKED_OPTIMIZATION
+#define CC_NON_BANKED __nonbanked
+#else
+#define CC_NON_BANKED
+#endif
 
 /* Generic types. */
 typedef unsigned short uip_stats_t;
diff --git a/cpu/cc253x/8051def.h b/cpu/cc253x/8051def.h
index e19fd8d31..7785d0bec 100644
--- a/cpu/cc253x/8051def.h
+++ b/cpu/cc253x/8051def.h
@@ -38,6 +38,13 @@
 #define CC_CONF_UNSIGNED_CHAR_BUGS	0
 #define CC_CONF_REGISTER_ARGS		0
 #define CC_CONF_FUNCTION_POINTER_KEYWORD __reentrant
+#define CC_CONF_NON_BANKED_OPTIMIZATION 1
+
+#if (defined(__SDCC_mcs51) || defined(SDCC_mcs51)) && CC_CONF_NON_BANKED_OPTIMIZATION
+#define CC_NON_BANKED __nonbanked
+#else
+#define CC_NON_BANKED
+#endif
 
 /* Generic types. */
 typedef unsigned short uip_stats_t;
diff --git a/examples/sensinode/border-router/border-router.c b/examples/sensinode/border-router/border-router.c
index a59ce6e0b..8c1e4952f 100644
--- a/examples/sensinode/border-router/border-router.c
+++ b/examples/sensinode/border-router/border-router.c
@@ -50,7 +50,7 @@ PROCESS(border_router_process, "Border Router process");
 AUTOSTART_PROCESSES(&border_router_process);
 /*---------------------------------------------------------------------------*/
 static void
-print_local_addresses(void)
+print_local_addresses(void) CC_NON_BANKED
 {
   int i;
   uint8_t state;
@@ -70,8 +70,9 @@ print_local_addresses(void)
   }
 }
 /*---------------------------------------------------------------------------*/
-void
-request_prefix(void) {
+static void
+request_prefix(void) CC_NON_BANKED
+{
   /* mess up uip_buf with a dirty request... */
   uip_buf[0] = '?';
   uip_buf[1] = 'P';
@@ -82,7 +83,8 @@ request_prefix(void) {
 /*---------------------------------------------------------------------------*/
 /* Set our prefix when we receive one over SLIP */
 void
-set_prefix_64(uip_ipaddr_t *prefix_64) {
+set_prefix_64(uip_ipaddr_t *prefix_64)
+{
   rpl_dag_t *dag;
   uip_ipaddr_t ipaddr;
   memcpy(&ipaddr, prefix_64, 16);
diff --git a/platform/cc2530dk/contiki-main.c b/platform/cc2530dk/contiki-main.c
index 23cb272c1..5767f3fe4 100644
--- a/platform/cc2530dk/contiki-main.c
+++ b/platform/cc2530dk/contiki-main.c
@@ -59,7 +59,7 @@ static unsigned long irq_energest = 0;
 #endif
 /*---------------------------------------------------------------------------*/
 static void
-fade(int l)
+fade(int l) CC_NON_BANKED
 {
   volatile int i, a;
   int k, j;
@@ -78,7 +78,7 @@ fade(int l)
 }
 /*---------------------------------------------------------------------------*/
 static void
-set_rime_addr(void)
+set_rime_addr(void) CC_NON_BANKED
 {
   char i;
 
@@ -136,10 +136,11 @@ set_rime_addr(void)
 #endif
 
   cc2530_rf_set_addr(IEEE802154_PANID);
+  return;
 }
 /*---------------------------------------------------------------------------*/
 int
-main(void)
+main(void) CC_NON_BANKED
 {
   /* Hardware initialization */
   clock_init();
diff --git a/platform/cc2530dk/viztool.c b/platform/cc2530dk/viztool.c
index bfa354982..642cb2f5c 100644
--- a/platform/cc2530dk/viztool.c
+++ b/platform/cc2530dk/viztool.c
@@ -73,7 +73,7 @@ extern uip_ds6_nbr_t uip_ds6_nbr_cache[UIP_DS6_NBR_NB];
 extern uip_ds6_defrt_t uip_ds6_defrt_list[UIP_DS6_DEFRT_NB];
 /*---------------------------------------------------------------------------*/
 static uint8_t
-process_request()
+process_request() CC_NON_BANKED
 {
   uint8_t len;
   uint8_t count; /* How many did we pack? */
@@ -251,7 +251,7 @@ process_request()
 PROCESS(viztool_process, "Network Visualization Tool Process");
 /*---------------------------------------------------------------------------*/
 static void
-tcpip_handler(void)
+tcpip_handler(void) CC_NON_BANKED
 {
   if(uip_newdata()) {
     memset(buf, 0, VIZTOOL_MAX_PAYLOAD_LEN);
diff --git a/platform/sensinode/apps/batmon/batmon.c b/platform/sensinode/apps/batmon/batmon.c
index 5f8797ef7..a4e59ab28 100644
--- a/platform/sensinode/apps/batmon/batmon.c
+++ b/platform/sensinode/apps/batmon/batmon.c
@@ -99,7 +99,7 @@ static struct etimer et;
 PROCESS(batmon_process, "Logger Process");
 /*---------------------------------------------------------------------------*/
 static int
-find_gap()
+find_gap() CC_NON_BANKED
 {
   uint8_t seq[3];
   uint32_t address = FLASH_START_ADDR;
@@ -124,7 +124,7 @@ find_gap()
 }
 /*---------------------------------------------------------------------------*/
 static void
-abort()
+abort() CC_NON_BANKED
 {
   PRINTF("BatMon: Abort\n");
   etimer_stop(&et);
diff --git a/platform/sensinode/contiki-sensinode-main.c b/platform/sensinode/contiki-sensinode-main.c
index 24862336a..905695526 100644
--- a/platform/sensinode/contiki-sensinode-main.c
+++ b/platform/sensinode/contiki-sensinode-main.c
@@ -72,7 +72,7 @@ static unsigned long irq_energest = 0;
 #endif
 /*---------------------------------------------------------------------------*/
 static void
-fade(int l)
+fade(int l) CC_NON_BANKED
 {
   volatile int i, a;
   int k, j;
@@ -91,7 +91,7 @@ fade(int l)
 }
 /*---------------------------------------------------------------------------*/
 static void
-set_rime_addr(void)
+set_rime_addr(void) CC_NON_BANKED
 {
   uint8_t *addr_long = NULL;
   uint16_t addr_short = 0;
diff --git a/platform/sensinode/dev/m25p16.c b/platform/sensinode/dev/m25p16.c
index 5239dbf74..d842a3421 100644
--- a/platform/sensinode/dev/m25p16.c
+++ b/platform/sensinode/dev/m25p16.c
@@ -63,7 +63,7 @@
 /*---------------------------------------------------------------------------*/
 /* Bit-Bang write a byte to the chip */
 static void
-bit_bang_write(uint8_t byte)
+bit_bang_write(uint8_t byte) CC_NON_BANKED
 {
   uint8_t i;
   uint8_t bit;
@@ -85,7 +85,7 @@ bit_bang_write(uint8_t byte)
 /*---------------------------------------------------------------------------*/
 /* Bit-Bang read a byte from the chip */
 static uint8_t
-bit_bang_read()
+bit_bang_read() CC_NON_BANKED
 {
   int8_t i;
   uint8_t bits = 0;
@@ -102,7 +102,7 @@ bit_bang_read()
 }
 /*---------------------------------------------------------------------------*/
 static void
-select()
+select() CC_NON_BANKED
 {
   /* Read current ser/par value */
   uint8_t ser_par = n740_ser_par_get();
@@ -116,7 +116,7 @@ select()
 }
 /*---------------------------------------------------------------------------*/
 static void
-deselect()
+deselect() CC_NON_BANKED
 {
   /* Read current ser/par value */
   uint8_t ser_par = n740_ser_par_get();
diff --git a/platform/sensinode/disco.c b/platform/sensinode/disco.c
index 12c1146cb..39e023980 100644
--- a/platform/sensinode/disco.c
+++ b/platform/sensinode/disco.c
@@ -95,7 +95,7 @@ __xdata __at(BOOTTY_CMD_LOCATION) static uint8_t bd;
 static void timer_handler(void * p);
 /*---------------------------------------------------------------------------*/
 static void
-abort()
+abort() CC_NON_BANKED
 {
   PRINTF("Disco: Abort @ %lu\n", clock_seconds());
   n740_analog_deactivate();
@@ -108,7 +108,7 @@ abort()
 }
 /*---------------------------------------------------------------------------*/
 static void
-restart_timer(uint16_t t)
+restart_timer(uint16_t t) CC_NON_BANKED
 {
   interval = t;
   ctimer_stop(&disco_timer);
@@ -160,7 +160,9 @@ timer_handler(void * p)
   }
 }
 /*---------------------------------------------------------------------------*/
-static uint8_t is_protected(uint8_t a) {
+static uint8_t
+is_protected(uint8_t a) CC_NON_BANKED
+{
   uint8_t bp = M25P16_BP() >> 2;
 
   if(bp > 5) {
@@ -176,7 +178,7 @@ static uint8_t is_protected(uint8_t a) {
 }
 /*---------------------------------------------------------------------------*/
 static uint8_t
-cmd_init()
+cmd_init() CC_NON_BANKED
 {
   PRINTF("Disco: Init 0x%02x\n", req->addr[0]);
   if(uip_datalen() != DISCO_LEN_INIT) {
@@ -209,7 +211,7 @@ cmd_init()
 }
 /*---------------------------------------------------------------------------*/
 static uint8_t
-cmd_write()
+cmd_write() CC_NON_BANKED
 {
   PRINTF("Disco: Write 0x%02x%02x%02x\n", req->addr[0], req->addr[1], req->addr[2]);
   if(uip_datalen() != DISCO_LEN_WRITE) {
@@ -228,7 +230,7 @@ cmd_write()
 }
 /*---------------------------------------------------------------------------*/
 static uint8_t
-cmd_switch()
+cmd_switch() CC_NON_BANKED
 {
   PRINTF("Disco: Switch 0x%02x\n", req->addr[0]);
   if(uip_datalen() != DISCO_LEN_SWITCH) {
@@ -253,7 +255,7 @@ cmd_switch()
 }
 /*---------------------------------------------------------------------------*/
 static uint8_t
-cmd_done()
+cmd_done() CC_NON_BANKED
 {
   PRINTF("Disco: Done\n");
   if(uip_datalen() != DISCO_LEN_DONE) {
@@ -268,7 +270,7 @@ cmd_done()
 }
 /*---------------------------------------------------------------------------*/
 static uint8_t
-event_handler(process_event_t ev)
+event_handler(process_event_t ev) CC_NON_BANKED
 {
   uint8_t rv = DISCO_RESPONSE_NONE;
 
diff --git a/platform/sensinode/viztool.c b/platform/sensinode/viztool.c
index bfa354982..642cb2f5c 100644
--- a/platform/sensinode/viztool.c
+++ b/platform/sensinode/viztool.c
@@ -73,7 +73,7 @@ extern uip_ds6_nbr_t uip_ds6_nbr_cache[UIP_DS6_NBR_NB];
 extern uip_ds6_defrt_t uip_ds6_defrt_list[UIP_DS6_DEFRT_NB];
 /*---------------------------------------------------------------------------*/
 static uint8_t
-process_request()
+process_request() CC_NON_BANKED
 {
   uint8_t len;
   uint8_t count; /* How many did we pack? */
@@ -251,7 +251,7 @@ process_request()
 PROCESS(viztool_process, "Network Visualization Tool Process");
 /*---------------------------------------------------------------------------*/
 static void
-tcpip_handler(void)
+tcpip_handler(void) CC_NON_BANKED
 {
   if(uip_newdata()) {
     memset(buf, 0, VIZTOOL_MAX_PAYLOAD_LEN);