diff --git a/os/rt/include/chbsem.h b/os/rt/include/chbsem.h
index 96d1ca2fb..336e6925f 100644
--- a/os/rt/include/chbsem.h
+++ b/os/rt/include/chbsem.h
@@ -267,7 +267,7 @@ static inline void chBSemSignalI(binary_semaphore_t *bsp) {
 
   chDbgCheckClassI();
 
-  if (bsp->bs_sem.s_cnt < 1) {
+  if (bsp->bs_sem.s_cnt < (cnt_t)1) {
     chSemSignalI(&bsp->bs_sem);
   }
 }
@@ -301,7 +301,7 @@ static inline bool chBSemGetStateI(binary_semaphore_t *bsp) {
 
   chDbgCheckClassI();
 
-  return (bsp->bs_sem.s_cnt > 0) ? false : true;
+  return (bsp->bs_sem.s_cnt > (cnt_t)0) ? false : true;
 }
 
 #endif /* CH_CFG_USE_SEMAPHORES == TRUE */
diff --git a/os/rt/include/chevents.h b/os/rt/include/chevents.h
index e58836f2e..8ac91d256 100644
--- a/os/rt/include/chevents.h
+++ b/os/rt/include/chevents.h
@@ -188,7 +188,7 @@ static inline void chEvtObjectInit(event_source_t *esp) {
  */
 static inline void chEvtRegisterMask(event_source_t *esp,
                                      event_listener_t *elp,
-                                     eventflags_t events) {
+                                     eventmask_t events) {
 
   chEvtRegisterMaskWithFlags(esp, elp, events, (eventflags_t)-1);
 }
@@ -236,7 +236,7 @@ static inline bool chEvtIsListeningI(event_source_t *esp) {
  */
 static inline void chEvtBroadcast(event_source_t *esp) {
 
-  chEvtBroadcastFlags(esp, 0);
+  chEvtBroadcastFlags(esp, (eventflags_t)0);
 }
 
 /**
@@ -253,7 +253,7 @@ static inline void chEvtBroadcast(event_source_t *esp) {
  */
 static inline void chEvtBroadcastI(event_source_t *esp) {
 
-  chEvtBroadcastFlagsI(esp, 0);
+  chEvtBroadcastFlagsI(esp, (eventflags_t)0);
 }
 
 #endif /* CH_CFG_USE_EVENTS == TRUE */
diff --git a/os/rt/include/chqueues.h b/os/rt/include/chqueues.h
index 079b417d5..2b4c660f3 100644
--- a/os/rt/include/chqueues.h
+++ b/os/rt/include/chqueues.h
@@ -41,8 +41,8 @@
 #define Q_OK            MSG_OK      /**< @brief Operation successful.       */
 #define Q_TIMEOUT       MSG_TIMEOUT /**< @brief Timeout condition.          */
 #define Q_RESET         MSG_RESET   /**< @brief Queue has been reset.       */
-#define Q_EMPTY         -3          /**< @brief Queue empty.                */
-#define Q_FULL          -4          /**< @brief Queue full,                 */
+#define Q_EMPTY         (msg_t)-3   /**< @brief Queue empty.                */
+#define Q_FULL          (msg_t)-4   /**< @brief Queue full,                 */
 /** @} */
 
 /*===========================================================================*/
diff --git a/os/rt/include/chschd.h b/os/rt/include/chschd.h
index 4d3319817..5d9829d57 100644
--- a/os/rt/include/chschd.h
+++ b/os/rt/include/chschd.h
@@ -36,48 +36,50 @@
  * @name    Wakeup status codes
  * @{
  */
-#define MSG_OK              0       /**< @brief Normal wakeup message.      */
-#define MSG_TIMEOUT         -1      /**< @brief Wakeup caused by a timeout
-                                         condition.                         */
-#define MSG_RESET           -2      /**< @brief Wakeup caused by a reset
-                                         condition.                         */
+#define MSG_OK              (msg_t)0    /**< @brief Normal wakeup message.  */
+#define MSG_TIMEOUT         (msg_t)-1   /**< @brief Wakeup caused by a timeout
+                                             condition.                     */
+#define MSG_RESET           (msg_t)-2   /**< @brief Wakeup caused by a reset
+                                             condition.                     */
 /** @} */
 
 /**
  * @name    Priority constants
  * @{
  */
-#define NOPRIO              0U      /**< @brief Ready list header priority. */
-#define IDLEPRIO            1U      /**< @brief Idle thread priority.       */
-#define LOWPRIO             2U      /**< @brief Lowest user priority.       */
-#define NORMALPRIO          64U     /**< @brief Normal user priority.       */
-#define HIGHPRIO            127U    /**< @brief Highest user priority.      */
-#define ABSPRIO             255U    /**< @brief Greatest possible priority. */
+#define NOPRIO              (tprio_t)0      /**< @brief Ready list header
+                                                 priority.                  */
+#define IDLEPRIO            (tprio_t)1      /**< @brief Idle priority.      */
+#define LOWPRIO             (tprio_t)2      /**< @brief Lowest priority.    */
+#define NORMALPRIO          (tprio_t)64     /**< @brief Normal priority.    */
+#define HIGHPRIO            (tprio_t)127    /**< @brief Highest priority.   */
+#define ABSPRIO             (tprio_t)255    /**< @brief Greatest priority.  */
 /** @} */
 
 /**
  * @name    Thread states
  * @{
  */
-#define CH_STATE_READY      0U      /**< @brief Waiting on the ready list.  */
-#define CH_STATE_CURRENT    1U      /**< @brief Currently running.          */
-#define CH_STATE_WTSTART    2U      /**< @brief Created but not started.    */
-#define CH_STATE_SUSPENDED  3U      /**< @brief Suspended state.            */
-#define CH_STATE_QUEUED     4U      /**< @brief Waiting on an I/O queue.    */
-#define CH_STATE_WTSEM      5U      /**< @brief Waiting on a semaphore.     */
-#define CH_STATE_WTMTX      6U      /**< @brief Waiting on a mutex.         */
-#define CH_STATE_WTCOND     7U      /**< @brief Waiting on a condition
-                                         variable.                          */
-#define CH_STATE_SLEEPING   8U      /**< @brief Waiting in @p chThdSleep()
-                                         or @p chThdSleepUntil().           */
-#define CH_STATE_WTEXIT     9U      /**< @brief Waiting in @p chThdWait().  */
-#define CH_STATE_WTOREVT    10U     /**< @brief Waiting for an event.       */
-#define CH_STATE_WTANDEVT   11U     /**< @brief Waiting for several events. */
-#define CH_STATE_SNDMSGQ    12U     /**< @brief Sending a message, in queue.*/
-#define CH_STATE_SNDMSG     13U     /**< @brief Sent a message, waiting
-                                         answer.                            */
-#define CH_STATE_WTMSG      14U     /**< @brief Waiting for a message.      */
-#define CH_STATE_FINAL      15U     /**< @brief Thread terminated.          */
+#define CH_STATE_READY      (tstate_t)0      /**< @brief Waiting on the
+                                                  ready list.               */
+#define CH_STATE_CURRENT    (tstate_t)1      /**< @brief Currently running. */
+#define CH_STATE_WTSTART    (tstate_t)2      /**< @brief Just created.      */
+#define CH_STATE_SUSPENDED  (tstate_t)3      /**< @brief Suspended state.   */
+#define CH_STATE_QUEUED     (tstate_t)4      /**< @brief On an I/O queue.   */
+#define CH_STATE_WTSEM      (tstate_t)5      /**< @brief On a semaphore.    */
+#define CH_STATE_WTMTX      (tstate_t)6      /**< @brief On a mutex.        */
+#define CH_STATE_WTCOND     (tstate_t)7      /**< @brief On a cond.variable.*/
+#define CH_STATE_SLEEPING   (tstate_t)8      /**< @brief Sleeping.          */
+#define CH_STATE_WTEXIT     (tstate_t)9      /**< @brief Waiting a thread.  */
+#define CH_STATE_WTOREVT    (tstate_t)10     /**< @brief One event.         */
+#define CH_STATE_WTANDEVT   (tstate_t)11     /**< @brief Several events.    */
+#define CH_STATE_SNDMSGQ    (tstate_t)12     /**< @brief Sending a message,
+                                                  in queue.                 */
+#define CH_STATE_SNDMSG     (tstate_t)13     /**< @brief Sent a message,
+                                                  waiting answer.          */
+#define CH_STATE_WTMSG      (tstate_t)14     /**< @brief Waiting for a
+                                                  message.                  */
+#define CH_STATE_FINAL      (tstate_t)15     /**< @brief Thread terminated. */
 
 /**
  * @brief   Thread states as array of strings.
@@ -94,13 +96,15 @@
  * @name    Thread flags and attributes
  * @{
  */
-#define CH_FLAG_MODE_MASK       3U  /**< @brief Thread memory mode mask.    */
-#define CH_FLAG_MODE_STATIC     0U  /**< @brief Static thread.              */
-#define CH_FLAG_MODE_HEAP       1U  /**< @brief Thread allocated from a
-                                         Memory Heap.                       */
-#define CH_FLAG_MODE_MEMPOOL    2U  /**< @brief Thread allocated from a
-                                         Memory Pool.                       */
-#define CH_FLAG_TERMINATE       4U  /**< @brief Termination requested flag. */
+#define CH_FLAG_MODE_MASK   (tmode_t)3U     /**< @brief Thread memory mode
+                                                 mask.                      */
+#define CH_FLAG_MODE_STATIC (tmode_t)0U     /**< @brief Static thread.      */
+#define CH_FLAG_MODE_HEAP   (tmode_t)1U     /**< @brief Thread allocated
+                                                 from a Memory Heap.        */
+#define CH_FLAG_MODE_MPOOL  (tmode_t)2U     /**< @brief Thread allocated
+                                                 from a Memory Pool.        */
+#define CH_FLAG_TERMINATE   (tmode_t)4U     /**< @brief Termination requested
+                                                 flag.                      */
 /** @} */
 
 /**
@@ -755,7 +759,7 @@ static inline void chSchPreemption(void) {
   tprio_t p2 = currp->p_prio;
 
 #if CH_CFG_TIME_QUANTUM > 0
-  if (currp->p_preempt > 0U) {
+  if (currp->p_preempt > (tslices_t)0) {
     if (p1 > p2) {
       chSchDoRescheduleAhead();
     }
diff --git a/os/rt/include/chthreads.h b/os/rt/include/chthreads.h
index 966f5de08..aca3e1d78 100644
--- a/os/rt/include/chthreads.h
+++ b/os/rt/include/chthreads.h
@@ -230,7 +230,7 @@ static inline bool chThdTerminatedX(thread_t *tp) {
  */
 static inline bool chThdShouldTerminateX(void) {
 
-  return (bool)((chThdGetSelfX()->p_flags & CH_FLAG_TERMINATE) != 0U);
+  return (bool)((chThdGetSelfX()->p_flags & CH_FLAG_TERMINATE) != (tmode_t)0);
 }
 
 /**
diff --git a/os/rt/include/chvt.h b/os/rt/include/chvt.h
index 2d7d36f29..01cfbdeee 100644
--- a/os/rt/include/chvt.h
+++ b/os/rt/include/chvt.h
@@ -451,7 +451,7 @@ static inline void chVTDoTickI(void) {
     virtual_timer_t *vtp;
 
     --ch.vtlist.vt_next->vt_delta;
-    while (ch.vtlist.vt_next->vt_delta == 0U) {
+    while (ch.vtlist.vt_next->vt_delta == (systime_t)0) {
       vtfunc_t fn;
 
       vtp = ch.vtlist.vt_next;
diff --git a/os/rt/ports/SIMIA32/chcore.h b/os/rt/ports/SIMIA32/chcore.h
index 943dbaf6e..b313cb9f9 100644
--- a/os/rt/ports/SIMIA32/chcore.h
+++ b/os/rt/ports/SIMIA32/chcore.h
@@ -276,7 +276,7 @@ static inline syssts_t port_get_irq_status(void) {
  */
 static inline bool port_irq_enabled(syssts_t sts) {
 
-  return (sts & 1U) == 0U;
+  return (sts & (syssts_t)1) == (syssts_t)0;
 }
 
 /**
diff --git a/os/rt/src/chdynamic.c b/os/rt/src/chdynamic.c
index 05cb3a265..ac4db6ba4 100644
--- a/os/rt/src/chdynamic.c
+++ b/os/rt/src/chdynamic.c
@@ -68,7 +68,7 @@
 thread_t *chThdAddRef(thread_t *tp) {
 
   chSysLock();
-  chDbgAssert(tp->p_refs < 255U, "too many references");
+  chDbgAssert(tp->p_refs < (trefs_t)255, "too many references");
   tp->p_refs++;
   chSysUnlock();
 
@@ -92,7 +92,7 @@ void chThdRelease(thread_t *tp) {
   trefs_t refs;
 
   chSysLock();
-  chDbgAssert(tp->p_refs > 0U, "not referenced");
+  chDbgAssert(tp->p_refs > (trefs_t)0, "not referenced");
   tp->p_refs--;
   refs = tp->p_refs;
   chSysUnlock();
@@ -100,7 +100,7 @@ void chThdRelease(thread_t *tp) {
   /* If the references counter reaches zero and the thread is in its
      terminated state then the memory can be returned to the proper
      allocator. Of course static threads are not affected.*/
-  if ((refs == 0U) && (tp->p_state == CH_STATE_FINAL)) {
+  if ((refs == (trefs_t)0) && (tp->p_state == CH_STATE_FINAL)) {
     switch (tp->p_flags & CH_FLAG_MODE_MASK) {
 #if CH_CFG_USE_HEAP == TRUE
     case CH_FLAG_MODE_HEAP:
@@ -111,7 +111,7 @@ void chThdRelease(thread_t *tp) {
       break;
 #endif
 #if CH_CFG_USE_MEMPOOLS == TRUE
-    case CH_FLAG_MODE_MEMPOOL:
+    case CH_FLAG_MODE_MPOOL:
 #if CH_CFG_USE_REGISTRY == TRUE
       REG_REMOVE(tp);
 #endif
@@ -224,7 +224,7 @@ thread_t *chThdCreateFromMemoryPool(memory_pool_t *mp, tprio_t prio,
 
   chSysLock();
   tp = chThdCreateI(wsp, mp->mp_object_size, prio, pf, arg);
-  tp->p_flags = CH_FLAG_MODE_MEMPOOL;
+  tp->p_flags = CH_FLAG_MODE_MPOOL;
   tp->p_mpool = mp;
   chSchWakeupS(tp, MSG_OK);
   chSysUnlock();
diff --git a/os/rt/src/chevents.c b/os/rt/src/chevents.c
index df5e4bfaa..96c1594d8 100644
--- a/os/rt/src/chevents.c
+++ b/os/rt/src/chevents.c
@@ -112,7 +112,7 @@ void chEvtRegisterMaskWithFlags(event_source_t *esp,
   esp->es_next     = elp;
   elp->el_listener = currp;
   elp->el_events   = events;
-  elp->el_flags    = 0;
+  elp->el_flags    = (eventflags_t)0;
   elp->el_wflags   = wflags;
   chSysUnlock();
 }
@@ -219,7 +219,8 @@ void chEvtBroadcastFlagsI(event_source_t *esp, eventflags_t flags) {
     elp->el_flags |= flags;
     /* When flags == 0 the thread will always be signaled because the
        source does not emit any flag.*/
-    if ((flags == 0U) || ((elp->el_flags & elp->el_wflags) != 0U)) {
+    if ((flags == (eventflags_t)0) ||
+        ((elp->el_flags & elp->el_wflags) != (eventflags_t)0)) {
       chEvtSignalI(elp->el_listener, elp->el_events);
     }
     elp = elp->el_next;
@@ -242,7 +243,7 @@ eventflags_t chEvtGetAndClearFlags(event_listener_t *elp) {
 
   chSysLock();
   flags = elp->el_flags;
-  elp->el_flags = 0;
+  elp->el_flags = (eventflags_t)0;
   chSysUnlock();
 
   return flags;
@@ -286,7 +287,7 @@ void chEvtSignalI(thread_t *tp, eventmask_t events) {
   tp->p_epending |= events;
   /* Test on the AND/OR conditions wait states.*/
   if (((tp->p_state == CH_STATE_WTOREVT) &&
-       ((tp->p_epending & tp->p_u.ewmask) != 0U)) ||
+       ((tp->p_epending & tp->p_u.ewmask) != (eventmask_t)0)) ||
       ((tp->p_state == CH_STATE_WTANDEVT) &&
        ((tp->p_epending & tp->p_u.ewmask) == tp->p_u.ewmask))) {
     tp->p_u.rdymsg = MSG_OK;
@@ -330,7 +331,7 @@ eventflags_t chEvtGetAndClearFlagsI(event_listener_t *elp) {
   eventflags_t flags;
 
   flags = elp->el_flags;
-  elp->el_flags = 0;
+  elp->el_flags = (eventflags_t)0;
 
   return flags;
 }
@@ -349,9 +350,9 @@ void chEvtDispatch(const evhandler_t *handlers, eventmask_t events) {
 
   chDbgCheck(handlers != NULL);
 
-  eid = 0;
-  while (events != 0U) {
-    if ((events & EVENT_MASK(eid)) != 0U) {
+  eid = (eventid_t)0;
+  while (events != (eventmask_t)0) {
+    if ((events & EVENT_MASK(eid)) != (eventmask_t)0) {
       chDbgAssert(handlers[eid] != NULL, "null handler");
       events &= ~EVENT_MASK(eid);
       handlers[eid](eid);
@@ -385,12 +386,12 @@ eventmask_t chEvtWaitOne(eventmask_t events) {
 
   chSysLock();
   m = ctp->p_epending & events;
-  if (m == 0U) {
+  if (m == (eventmask_t)0) {
     ctp->p_u.ewmask = events;
     chSchGoSleepS(CH_STATE_WTOREVT);
     m = ctp->p_epending & events;
   }
-  m ^= m & (m - 1U);
+  m ^= m & (m - (eventmask_t)1);
   ctp->p_epending &= ~m;
   chSysUnlock();
 
@@ -415,7 +416,7 @@ eventmask_t chEvtWaitAny(eventmask_t events) {
 
   chSysLock();
   m = ctp->p_epending & events;
-  if (m == 0U) {
+  if (m == (eventmask_t)0) {
     ctp->p_u.ewmask = events;
     chSchGoSleepS(CH_STATE_WTOREVT);
     m = ctp->p_epending & events;
@@ -481,7 +482,7 @@ eventmask_t chEvtWaitOneTimeout(eventmask_t events, systime_t time) {
 
   chSysLock();
   m = ctp->p_epending & events;
-  if (m == 0U) {
+  if (m == (eventmask_t)0) {
     if (TIME_IMMEDIATE == time) {
       chSysUnlock();
       return (eventmask_t)0;
@@ -493,7 +494,7 @@ eventmask_t chEvtWaitOneTimeout(eventmask_t events, systime_t time) {
     }
     m = ctp->p_epending & events;
   }
-  m ^= m & (m - 1U);
+  m ^= m & (m - (eventmask_t)1);
   ctp->p_epending &= ~m;
   chSysUnlock();
 
@@ -524,7 +525,7 @@ eventmask_t chEvtWaitAnyTimeout(eventmask_t events, systime_t time) {
 
   chSysLock();
   m = ctp->p_epending & events;
-  if (m == 0U) {
+  if (m == (eventmask_t)0) {
     if (TIME_IMMEDIATE == time) {
       chSysUnlock();
       return (eventmask_t)0;
diff --git a/os/rt/src/chmboxes.c b/os/rt/src/chmboxes.c
index 6c518676b..21f8ce55e 100644
--- a/os/rt/src/chmboxes.c
+++ b/os/rt/src/chmboxes.c
@@ -85,14 +85,14 @@
  */
 void chMBObjectInit(mailbox_t *mbp, msg_t *buf, cnt_t n) {
 
-  chDbgCheck((mbp != NULL) && (buf != NULL) && (n > 0));
+  chDbgCheck((mbp != NULL) && (buf != NULL) && (n > (cnt_t)0));
 
   mbp->mb_buffer = buf;
   mbp->mb_rdptr = buf;
   mbp->mb_wrptr = buf;
   mbp->mb_top = &buf[n];
   chSemObjectInit(&mbp->mb_emptysem, n);
-  chSemObjectInit(&mbp->mb_fullsem, 0);
+  chSemObjectInit(&mbp->mb_fullsem, (cnt_t)0);
 }
 
 /**
@@ -129,7 +129,7 @@ void chMBResetI(mailbox_t *mbp) {
   mbp->mb_wrptr = mbp->mb_buffer;
   mbp->mb_rdptr = mbp->mb_buffer;
   chSemResetI(&mbp->mb_emptysem, (cnt_t)(mbp->mb_top - mbp->mb_buffer));
-  chSemResetI(&mbp->mb_fullsem, 0);
+  chSemResetI(&mbp->mb_fullsem, (cnt_t)0);
 }
 
 /**
@@ -218,7 +218,7 @@ msg_t chMBPostI(mailbox_t *mbp, msg_t msg) {
   chDbgCheckClassI();
   chDbgCheck(mbp != NULL);
 
-  if (chSemGetCounterI(&mbp->mb_emptysem) <= 0) {
+  if (chSemGetCounterI(&mbp->mb_emptysem) <= (cnt_t)0) {
     return MSG_TIMEOUT;
   }
 
@@ -318,7 +318,7 @@ msg_t chMBPostAheadI(mailbox_t *mbp, msg_t msg) {
   chDbgCheckClassI();
   chDbgCheck(mbp != NULL);
 
-  if (chSemGetCounterI(&mbp->mb_emptysem) <= 0) {
+  if (chSemGetCounterI(&mbp->mb_emptysem) <= (cnt_t)0) {
     return MSG_TIMEOUT;
   }
   chSemFastWaitI(&mbp->mb_emptysem);
@@ -417,7 +417,7 @@ msg_t chMBFetchI(mailbox_t *mbp, msg_t *msgp) {
   chDbgCheckClassI();
   chDbgCheck((mbp != NULL) && (msgp != NULL));
 
-  if (chSemGetCounterI(&mbp->mb_fullsem) <= 0) {
+  if (chSemGetCounterI(&mbp->mb_fullsem) <= (cnt_t)0) {
     return MSG_TIMEOUT;
   }
   chSemFastWaitI(&mbp->mb_fullsem);
diff --git a/os/rt/src/chregistry.c b/os/rt/src/chregistry.c
index 162d69bf2..aacadf22c 100644
--- a/os/rt/src/chregistry.c
+++ b/os/rt/src/chregistry.c
@@ -164,7 +164,7 @@ thread_t *chRegNextThread(thread_t *tp) {
   }
 #if CH_CFG_USE_DYNAMIC == TRUE
   else {
-    chDbgAssert(ntp->p_refs < 255U, "too many references");
+    chDbgAssert(ntp->p_refs < (trefs_t)255, "too many references");
     ntp->p_refs++;
   }
 #endif
diff --git a/os/rt/src/chschd.c b/os/rt/src/chschd.c
index 91b982b0c..e53384b3d 100644
--- a/os/rt/src/chschd.c
+++ b/os/rt/src/chschd.c
@@ -257,7 +257,7 @@ void chSchGoSleepS(tstate_t newstate) {
 #if CH_CFG_TIME_QUANTUM > 0
   /* The thread is renouncing its remaining time slices so it will have a new
      time quantum when it will wakeup.*/
-  otp->p_preempt = CH_CFG_TIME_QUANTUM;
+  otp->p_preempt = (tslices_t)CH_CFG_TIME_QUANTUM;
 #endif
   setcurrp(queue_fifo_remove(&ch.rlist.r_queue));
 #if defined(CH_CFG_IDLE_ENTER_HOOK)
@@ -430,7 +430,7 @@ bool chSchIsPreemptionRequired(void) {
      if the first thread on the ready queue has a higher priority.
      Otherwise, if the running thread has used up its time quantum, reschedule
      if the first thread on the ready queue has equal or higher priority.*/
-  return (currp->p_preempt > 0U) ? (p1 > p2) : (p1 >= p2);
+  return (currp->p_preempt > (tslices_t)0) ? (p1 > p2) : (p1 >= p2);
 #else
   /* If the round robin preemption feature is not enabled then performs a
      simpler comparison.*/
@@ -461,7 +461,7 @@ void chSchDoRescheduleBehind(void) {
 #endif
   currp->p_state = CH_STATE_CURRENT;
 #if CH_CFG_TIME_QUANTUM > 0
-  otp->p_preempt = CH_CFG_TIME_QUANTUM;
+  otp->p_preempt = (tslices_t)CH_CFG_TIME_QUANTUM;
 #endif
   (void) chSchReadyI(otp);
   chSysSwitch(currp, otp);
@@ -518,7 +518,7 @@ void chSchDoReschedule(void) {
 #if CH_CFG_TIME_QUANTUM > 0
   /* If CH_CFG_TIME_QUANTUM is enabled then there are two different scenarios
      to handle on preemption: time quantum elapsed or not.*/
-  if (currp->p_preempt == 0U) {
+  if (currp->p_preempt == (tslices_t)0) {
     /* The thread consumed its time quantum so it is enqueued behind threads
        with same priority level, however, it acquires a new time quantum.*/
     chSchDoRescheduleBehind();
diff --git a/os/rt/src/chsem.c b/os/rt/src/chsem.c
index 30a68e035..4a891b521 100644
--- a/os/rt/src/chsem.c
+++ b/os/rt/src/chsem.c
@@ -96,7 +96,7 @@
  */
 void chSemObjectInit(semaphore_t *sp, cnt_t n) {
 
-  chDbgCheck((sp != NULL) && (n >= 0));
+  chDbgCheck((sp != NULL) && (n >= (cnt_t)0));
 
   queue_init(&sp->s_queue);
   sp->s_cnt = n;
@@ -148,14 +148,14 @@ void chSemResetI(semaphore_t *sp, cnt_t n) {
   cnt_t cnt;
 
   chDbgCheckClassI();
-  chDbgCheck((sp != NULL) && (n >= 0));
-  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
-              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
+  chDbgCheck((sp != NULL) && (n >= (cnt_t)0));
+  chDbgAssert(((sp->s_cnt >= (cnt_t)0) && queue_isempty(&sp->s_queue)) ||
+              ((sp->s_cnt < (cnt_t)0) && queue_notempty(&sp->s_queue)),
               "inconsistent semaphore");
 
   cnt = sp->s_cnt;
   sp->s_cnt = n;
-  while (++cnt <= 0) {
+  while (++cnt <= (cnt_t)0) {
     chSchReadyI(queue_lifo_remove(&sp->s_queue))->p_u.rdymsg = MSG_RESET;
   }
 }
@@ -198,11 +198,11 @@ msg_t chSemWaitS(semaphore_t *sp) {
 
   chDbgCheckClassS();
   chDbgCheck(sp != NULL);
-  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
-              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
+  chDbgAssert(((sp->s_cnt >= (cnt_t)0) && queue_isempty(&sp->s_queue)) ||
+              ((sp->s_cnt < (cnt_t)0) && queue_notempty(&sp->s_queue)),
               "inconsistent semaphore");
 
-  if (--sp->s_cnt < 0) {
+  if (--sp->s_cnt < (cnt_t)0) {
     currp->p_u.wtsemp = sp;
     sem_insert(currp, &sp->s_queue);
     chSchGoSleepS(CH_STATE_WTSEM);
@@ -265,11 +265,11 @@ msg_t chSemWaitTimeoutS(semaphore_t *sp, systime_t time) {
 
   chDbgCheckClassS();
   chDbgCheck(sp != NULL);
-  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
-              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
+  chDbgAssert(((sp->s_cnt >= (cnt_t)0) && queue_isempty(&sp->s_queue)) ||
+              ((sp->s_cnt < (cnt_t)0) && queue_notempty(&sp->s_queue)),
               "inconsistent semaphore");
 
-  if (--sp->s_cnt < 0) {
+  if (--sp->s_cnt < (cnt_t)0) {
     if (TIME_IMMEDIATE == time) {
       sp->s_cnt++;
 
@@ -294,12 +294,12 @@ msg_t chSemWaitTimeoutS(semaphore_t *sp, systime_t time) {
 void chSemSignal(semaphore_t *sp) {
 
   chDbgCheck(sp != NULL);
-  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
-              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
+  chDbgAssert(((sp->s_cnt >= (cnt_t)0) && queue_isempty(&sp->s_queue)) ||
+              ((sp->s_cnt < (cnt_t)0) && queue_notempty(&sp->s_queue)),
               "inconsistent semaphore");
 
   chSysLock();
-  if (++sp->s_cnt <= 0) {
+  if (++sp->s_cnt <= (cnt_t)0) {
     chSchWakeupS(queue_fifo_remove(&sp->s_queue), MSG_OK);
   }
   chSysUnlock();
@@ -320,11 +320,11 @@ void chSemSignalI(semaphore_t *sp) {
 
   chDbgCheckClassI();
   chDbgCheck(sp != NULL);
-  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
-              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
+  chDbgAssert(((sp->s_cnt >= (cnt_t)0) && queue_isempty(&sp->s_queue)) ||
+              ((sp->s_cnt < (cnt_t)0) && queue_notempty(&sp->s_queue)),
               "inconsistent semaphore");
 
-  if (++sp->s_cnt <= 0) {
+  if (++sp->s_cnt <= (cnt_t)0) {
     /* Note, it is done this way in order to allow a tail call on
              chSchReadyI().*/
     thread_t *tp = queue_fifo_remove(&sp->s_queue);
@@ -349,13 +349,13 @@ void chSemSignalI(semaphore_t *sp) {
 void chSemAddCounterI(semaphore_t *sp, cnt_t n) {
 
   chDbgCheckClassI();
-  chDbgCheck((sp != NULL) && (n > 0));
-  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
-              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
+  chDbgCheck((sp != NULL) && (n > (cnt_t)0));
+  chDbgAssert(((sp->s_cnt >= (cnt_t)0) && queue_isempty(&sp->s_queue)) ||
+              ((sp->s_cnt < (cnt_t)0) && queue_notempty(&sp->s_queue)),
               "inconsistent semaphore");
 
-  while (n > 0) {
-    if (++sp->s_cnt <= 0) {
+  while (n > (cnt_t)0) {
+    if (++sp->s_cnt <= (cnt_t)0) {
       chSchReadyI(queue_fifo_remove(&sp->s_queue))->p_u.rdymsg = MSG_OK;
     }
     n--;
@@ -379,18 +379,18 @@ msg_t chSemSignalWait(semaphore_t *sps, semaphore_t *spw) {
   msg_t msg;
 
   chDbgCheck((sps != NULL) && (spw != NULL));
-  chDbgAssert(((sps->s_cnt >= 0) && queue_isempty(&sps->s_queue)) ||
-              ((sps->s_cnt < 0) && queue_notempty(&sps->s_queue)),
+  chDbgAssert(((sps->s_cnt >= (cnt_t)0) && queue_isempty(&sps->s_queue)) ||
+              ((sps->s_cnt < (cnt_t)0) && queue_notempty(&sps->s_queue)),
               "inconsistent semaphore");
-  chDbgAssert(((spw->s_cnt >= 0) && queue_isempty(&spw->s_queue)) ||
-              ((spw->s_cnt < 0) && queue_notempty(&spw->s_queue)),
+  chDbgAssert(((spw->s_cnt >= (cnt_t)0) && queue_isempty(&spw->s_queue)) ||
+              ((spw->s_cnt < (cnt_t)0) && queue_notempty(&spw->s_queue)),
               "inconsistent semaphore");
 
   chSysLock();
-  if (++sps->s_cnt <= 0) {
+  if (++sps->s_cnt <= (cnt_t)0) {
     chSchReadyI(queue_fifo_remove(&sps->s_queue))->p_u.rdymsg = MSG_OK;
   }
-  if (--spw->s_cnt < 0) {
+  if (--spw->s_cnt < (cnt_t)0) {
     thread_t *ctp = currp;
     sem_insert(ctp, &spw->s_queue);
     ctp->p_u.wtsemp = spw;
diff --git a/os/rt/src/chsys.c b/os/rt/src/chsys.c
index 44c4fc567..a9fd3aa53 100644
--- a/os/rt/src/chsys.c
+++ b/os/rt/src/chsys.c
@@ -188,7 +188,7 @@ void chSysTimerHandlerI(void) {
 
 #if CH_CFG_TIME_QUANTUM > 0
   /* Running thread has not used up quantum yet? */
-  if (currp->p_preempt > 0U) {
+  if (currp->p_preempt > (tslices_t)0) {
     /* Decrement remaining quantum.*/
     currp->p_preempt--;
   }
diff --git a/os/rt/src/chthreads.c b/os/rt/src/chthreads.c
index 491f416d5..9c18788c0 100644
--- a/os/rt/src/chthreads.c
+++ b/os/rt/src/chthreads.c
@@ -94,20 +94,20 @@ thread_t *_thread_init(thread_t *tp, tprio_t prio) {
   tp->p_state = CH_STATE_WTSTART;
   tp->p_flags = CH_FLAG_MODE_STATIC;
 #if CH_CFG_TIME_QUANTUM > 0
-  tp->p_preempt = CH_CFG_TIME_QUANTUM;
+  tp->p_preempt = (tslices_t)CH_CFG_TIME_QUANTUM;
 #endif
 #if CH_CFG_USE_MUTEXES == TRUE
   tp->p_realprio = prio;
   tp->p_mtxlist = NULL;
 #endif
 #if CH_CFG_USE_EVENTS == TRUE
-  tp->p_epending = 0;
+  tp->p_epending = (eventmask_t)0;
 #endif
 #if CH_DBG_THREADS_PROFILING == TRUE
-  tp->p_time = 0;
+  tp->p_time = (systime_t)0;
 #endif
 #if CH_CFG_USE_DYNAMIC == TRUE
-  tp->p_refs = 1;
+  tp->p_refs = (trefs_t)1;
 #endif
 #if CH_CFG_USE_REGISTRY == TRUE
   tp->p_name = NULL;
@@ -333,7 +333,7 @@ void chThdSleepUntil(systime_t time) {
 
   chSysLock();
   time -= chVTGetSystemTimeX();
-  if (time > 0U) {
+  if (time > (systime_t)0) {
     chThdSleepS(time);
   }
   chSysUnlock();
@@ -480,7 +480,7 @@ msg_t chThdWait(thread_t *tp) {
   chSysLock();
   chDbgAssert(tp != currp, "waiting self");
 #if CH_CFG_USE_DYNAMIC == TRUE
-  chDbgAssert(tp->p_refs > 0U, "not referenced");
+  chDbgAssert(tp->p_refs > (trefs_t)0, "not referenced");
 #endif
   if (tp->p_state != CH_STATE_FINAL) {
     list_insert(currp, &tp->p_waiting);
diff --git a/os/rt/src/chvt.c b/os/rt/src/chvt.c
index d802bc0c3..61fa7e056 100644
--- a/os/rt/src/chvt.c
+++ b/os/rt/src/chvt.c
@@ -64,9 +64,9 @@ void _vt_init(void) {
   ch.vtlist.vt_prev = (virtual_timer_t *)&ch.vtlist;
   ch.vtlist.vt_delta = (systime_t)-1;
 #if CH_CFG_ST_TIMEDELTA == 0
-  ch.vtlist.vt_systime = 0;
+  ch.vtlist.vt_systime = (systime_t)0;
 #else /* CH_CFG_ST_TIMEDELTA > 0 */
-  ch.vtlist.vt_lasttime = 0;
+  ch.vtlist.vt_lasttime = (systime_t)0;
 #endif /* CH_CFG_ST_TIMEDELTA > 0 */
 }
 
diff --git a/test/rt/testbuild/pclint/waivers.lnt b/test/rt/testbuild/pclint/waivers.lnt
index 1acdaf818..03ccb7a09 100644
--- a/test/rt/testbuild/pclint/waivers.lnt
+++ b/test/rt/testbuild/pclint/waivers.lnt
@@ -7,6 +7,24 @@
 +libh(stm32f4xx.h)
 +libh(*_lld.h)
 
+/* Reinforcing type checking for some critical types even if not required by
+   MISRA.*/
+-strong(AJX, systime_t)
+-strong(AJX, rtcnt_t)
+-strong(AJX, rttime_t)
+-strong(AJX, syssts_t)
+-strong(AJX, msg_t)
+-strong(AJX, tmode_t)
+-strong(AJX, tstate_t)
+-strong(AJX, trefs_t)
+-strong(AJX, tslices_t)
+-strong(AJX, tprio_t)
+-strong(AJX, cnt_t)
+-strong(AJX, ucnt_t)
+-strong(AJX, eventid_t)
+-strong(AJX, eventmask_t)
+-strong(AJX, eventflags_t)
+
 /* Permitting anonymous unions.*/
 +fan