diff --git a/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_DYNAMIC/cfg/chconf.h b/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_DYNAMIC/cfg/chconf.h
index bb68563a0..33599cb21 100644
--- a/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_DYNAMIC/cfg/chconf.h
+++ b/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_DYNAMIC/cfg/chconf.h
@@ -805,6 +805,10 @@
 /* Port-specific settings (override port settings defaulted in chcore.h).    */
 /*===========================================================================*/
 
+#define PORT_USE_SYSCALL                    TRUE
+
+#define PORT_SWITCHED_REGIONS_NUMBER        2
+
 #endif  /* CHCONF_H */
 
 /** @} */
diff --git a/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_STATIC/cfg/chconf.h b/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_STATIC/cfg/chconf.h
index bb68563a0..d54e1af95 100644
--- a/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_STATIC/cfg/chconf.h
+++ b/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST_STATIC/cfg/chconf.h
@@ -805,6 +805,8 @@
 /* Port-specific settings (override port settings defaulted in chcore.h).    */
 /*===========================================================================*/
 
+#define PORT_USE_SYSCALL                    TRUE
+
 #endif  /* CHCONF_H */
 
 /** @} */
diff --git a/os/common/ports/ARMv7-M/chcore.c b/os/common/ports/ARMv7-M/chcore.c
index dfa060e46..2a55387e7 100644
--- a/os/common/ports/ARMv7-M/chcore.c
+++ b/os/common/ports/ARMv7-M/chcore.c
@@ -58,13 +58,13 @@ __attribute__((noinline))
 void port_syslock_noinline(void) {
 
   port_lock();
-  _stats_start_measure_crit_thd();
-  _dbg_check_lock();
+  __stats_start_measure_crit_thd();
+  __dbg_check_lock();
 }
 
 uint32_t port_get_s_psp(void) {
 
-  return (uint32_t)currp->ctx.syscall.psp;
+  return (uint32_t)__sch_get_currthread()->ctx.syscall.psp;
 }
 
 __attribute__((weak))
@@ -144,7 +144,7 @@ void SVC_Handler(void) {
     struct port_extctx *newctxp;
 
     /* Supervisor PSP from the thread context structure.*/
-    s_psp = (uint32_t)currp->ctx.syscall.psp;
+    s_psp = (uint32_t)__sch_get_currthread()->ctx.syscall.psp;
 
     /* Pushing the port_linkctx into the supervisor stack.*/
     s_psp -= sizeof (struct port_linkctx);
@@ -334,7 +334,7 @@ void __port_irq_epilogue(void) {
         __set_CONTROL(control & ~1U);
 
         /* Switching to S-PSP taking it from the thread context.*/
-        s_psp = (uint32_t)currp->ctx.syscall.psp;
+        s_psp = (uint32_t)__sch_get_currthread()->ctx.syscall.psp;
 
         /* Pushing the middle context for returning to the original frame
            and mode.*/
diff --git a/os/rt/include/chmtx.h b/os/rt/include/chmtx.h
index 6030d4317..8fc3d60cd 100644
--- a/os/rt/include/chmtx.h
+++ b/os/rt/include/chmtx.h
@@ -92,6 +92,12 @@ struct ch_mutex {
  */
 #define MUTEX_DECL(name) mutex_t name = __MUTEX_DATA(name)
 
+#if CH_CFG_USE_MESSAGES_PRIORITY == TRUE
+#define __ch_msg_insert(tp, qp) ch_sch_prio_insert(&tp->hdr.queue, qp)
+#else
+#define __ch_msg_insert(tp, qp) ch_queue_insert(&tp->hdr.queue, qp)
+#endif
+
 /*===========================================================================*/
 /* External declarations.                                                    */
 /*===========================================================================*/
diff --git a/os/rt/src/chmsg.c b/os/rt/src/chmsg.c
index a3e712428..a6f496f04 100644
--- a/os/rt/src/chmsg.c
+++ b/os/rt/src/chmsg.c
@@ -63,12 +63,6 @@
 /* Module local functions.                                                   */
 /*===========================================================================*/
 
-#if CH_CFG_USE_MESSAGES_PRIORITY == TRUE
-#define msg_insert(tp, qp) ch_sch_prio_insert(&tp->hdr.queue, qp)
-#else
-#define msg_insert(tp, qp) ch_queue_insert(&tp->hdr.queue, qp)
-#endif
-
 /*===========================================================================*/
 /* Module exported functions.                                                */
 /*===========================================================================*/
@@ -91,7 +85,7 @@ msg_t chMsgSend(thread_t *tp, msg_t msg) {
 
   chSysLock();
   currtp->u.sentmsg = msg;
-  msg_insert(currtp, &tp->msgqueue);
+  __ch_msg_insert(currtp, &tp->msgqueue);
   if (tp->state == CH_STATE_WTMSG) {
     (void) chSchReadyI(tp);
   }
diff --git a/os/sb/host/sbhost.c b/os/sb/host/sbhost.c
index af6d3b038..83d37b3c3 100644
--- a/os/sb/host/sbhost.c
+++ b/os/sb/host/sbhost.c
@@ -163,7 +163,7 @@ void sbStart(sb_class_t *sbcp, const sb_config_t *config) {
 msg_t sbSendMessageTimeout(sb_class_t *sbcp,
                            msg_t msg,
                            sysinterval_t timeout) {
-  thread_t *ctp = currp;
+  thread_t *ctp = __sch_get_currthread();
 
   chDbgCheck(sbcp != NULL);
 
@@ -171,7 +171,7 @@ msg_t sbSendMessageTimeout(sb_class_t *sbcp,
 
   /* Sending the message.*/
   ctp->u.sentmsg = msg;
-  __msg_insert(ctp, &sbcp->tp->msgqueue);
+  __ch_msg_insert(ctp, &sbcp->tp->msgqueue);
   if (sbcp->tp->state == CH_STATE_WTMSG) {
     (void) chSchReadyI(sbcp->tp);
   }