diff --git a/arch/z80/src/common/up_assert.c b/arch/z80/src/common/up_assert.c
index a848172b24c..ee290781e09 100644
--- a/arch/z80/src/common/up_assert.c
+++ b/arch/z80/src/common/up_assert.c
@@ -91,7 +91,7 @@ static void _up_assert(int errorcode) /* noreturn_function */
 {
   /* Are we in an interrupt handler or the idle task? */
 
-  if (up_interrupt_context() || ((FAR struct tcb_s*)g_readytorun.head)->pid == 0)
+  if (up_interrupt_context() || this_task()->pid == 0)
     {
        (void)irqsave();
         for (;;)
@@ -150,7 +150,7 @@ void up_assert(void)
 #endif
 {
 #if CONFIG_TASK_NAME_SIZE > 0
-  struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
+  struct tcb_s *rtcb = this_task();
 #endif
 
   board_autoled_on(LED_ASSERTION);
@@ -181,7 +181,7 @@ void up_assert(void)
 #endif
 
 #ifdef CONFIG_BOARD_CRASHDUMP
-  board_crashdump(up_getsp(), g_readytorun.head, filename, lineno);
+  board_crashdump(up_getsp(), this_task(), filename, lineno);
 #endif
 
   _up_assert(EXIT_FAILURE);
diff --git a/arch/z80/src/common/up_blocktask.c b/arch/z80/src/common/up_blocktask.c
index 5ba6faebd59..831de41317d 100644
--- a/arch/z80/src/common/up_blocktask.c
+++ b/arch/z80/src/common/up_blocktask.c
@@ -77,7 +77,7 @@
 
 void up_block_task(FAR struct tcb_s *tcb, tstate_t task_state)
 {
-  FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
+  FAR struct tcb_s *rtcb = this_task();
   bool switch_needed;
 
   /* Verify that the context switch can be performed */
@@ -100,7 +100,7 @@ void up_block_task(FAR struct tcb_s *tcb, tstate_t task_state)
 
   sched_addblocked(tcb, (tstate_t)task_state);
 
-  /* If there are any pending tasks, then add them to the g_readytorun
+  /* If there are any pending tasks, then add them to the ready-to-run
    * task list now
    */
 
@@ -128,10 +128,10 @@ void up_block_task(FAR struct tcb_s *tcb, tstate_t task_state)
           SAVE_IRQCONTEXT(rtcb);
 
           /* Restore the exception context of the rtcb at the (new) head
-           * of the g_readytorun task list.
+           * of the ready-to-run task list.
            */
 
-          rtcb = (FAR struct tcb_s*)g_readytorun.head;
+          rtcb = this_task();
 
           /* Reset scheduler parameters */
 
@@ -146,17 +146,17 @@ void up_block_task(FAR struct tcb_s *tcb, tstate_t task_state)
         }
 
       /* Copy the user C context into the TCB at the (old) head of the
-       * g_readytorun Task list. if SAVE_USERCONTEXT returns a non-zero
+       * ready-to-run Task list. if SAVE_USERCONTEXT returns a non-zero
        * value, then this is really the previously running task restarting!
        */
 
       else if (!SAVE_USERCONTEXT(rtcb))
         {
           /* Restore the exception context of the rtcb at the (new) head
-           * of the g_readytorun task list.
+           * of the ready-to-run task list.
            */
 
-          rtcb = (FAR struct tcb_s*)g_readytorun.head;
+          rtcb = this_task();
 
 #ifdef CONFIG_ARCH_ADDRENV
          /* Make sure that the address environment for the previously
diff --git a/arch/z80/src/common/up_exit.c b/arch/z80/src/common/up_exit.c
index 2514ceb1240..3488fdbdc83 100644
--- a/arch/z80/src/common/up_exit.c
+++ b/arch/z80/src/common/up_exit.c
@@ -164,7 +164,7 @@ void _exit(int status)
    * head of the list.
    */
 
-  tcb = (FAR struct tcb_s*)g_readytorun.head;
+  tcb = this_task();
   slldbg("New Active Task TCB=%p\n", tcb);
 
 #ifdef CONFIG_ARCH_ADDRENV
diff --git a/arch/z80/src/common/up_releasepending.c b/arch/z80/src/common/up_releasepending.c
index 4350c15dc81..e4bc07a78fb 100644
--- a/arch/z80/src/common/up_releasepending.c
+++ b/arch/z80/src/common/up_releasepending.c
@@ -68,11 +68,11 @@
 
 void up_release_pending(void)
 {
-  FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
+  FAR struct tcb_s *rtcb = this_task();
 
   slldbg("From TCB=%p\n", rtcb);
 
-  /* Merge the g_pendingtasks list into the g_readytorun task list */
+  /* Merge the g_pendingtasks list into the ready-to-run task list */
 
   /* sched_lock(); */
   if (sched_mergepending())
@@ -96,10 +96,10 @@ void up_release_pending(void)
            SAVE_IRQCONTEXT(rtcb);
 
           /* Restore the exception context of the rtcb at the (new) head
-           * of the g_readytorun task list.
+           * of the ready-to-run task list.
            */
 
-          rtcb = (FAR struct tcb_s*)g_readytorun.head;
+          rtcb = this_task();
 
           /* Update scheduler parameters */
 
@@ -122,10 +122,10 @@ void up_release_pending(void)
       else if (!SAVE_USERCONTEXT(rtcb))
         {
           /* Restore the exception context of the rtcb at the (new) head
-           * of the g_readytorun task list.
+           * of the ready-to-run task list.
            */
 
-          rtcb = (FAR struct tcb_s*)g_readytorun.head;
+          rtcb = this_task();
 
 #ifdef CONFIG_ARCH_ADDRENV
           /* Make sure that the address environment for the previously
diff --git a/arch/z80/src/common/up_reprioritizertr.c b/arch/z80/src/common/up_reprioritizertr.c
index 99ed783d7a7..d7102775631 100644
--- a/arch/z80/src/common/up_reprioritizertr.c
+++ b/arch/z80/src/common/up_reprioritizertr.c
@@ -95,7 +95,7 @@ void up_reprioritize_rtr(FAR struct tcb_s *tcb, uint8_t priority)
     }
   else
     {
-      FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
+      FAR struct tcb_s *rtcb = this_task();
       bool switch_needed;
 
       slldbg("TCB=%p PRI=%d\n", tcb, priority);
@@ -150,10 +150,10 @@ void up_reprioritize_rtr(FAR struct tcb_s *tcb, uint8_t priority)
                SAVE_IRQCONTEXT(rtcb);
 
               /* Restore the exception context of the rtcb at the (new) head
-               * of the g_readytorun task list.
+               * of the ready-to-run task list.
                */
 
-              rtcb = (FAR struct tcb_s*)g_readytorun.head;
+              rtcb = this_task();
 
               /* Update scheduler parameters */
 
@@ -168,17 +168,17 @@ void up_reprioritize_rtr(FAR struct tcb_s *tcb, uint8_t priority)
             }
 
           /* Copy the exception context into the TCB at the (old) head of the
-           * g_readytorun Task list. if SAVE_USERCONTEXT returns a non-zero
+           * ready-to-run Task list. if SAVE_USERCONTEXT returns a non-zero
            * value, then this is really the previously running task restarting!
            */
 
           else if (!SAVE_USERCONTEXT(rtcb))
             {
               /* Restore the exception context of the rtcb at the (new) head
-               * of the g_readytorun task list.
+               * of the ready-to-run task list.
                */
 
-              rtcb = (FAR struct tcb_s*)g_readytorun.head;
+              rtcb = this_task();
 
 #ifdef CONFIG_ARCH_ADDRENV
               /* Make sure that the address environment for the previously
diff --git a/arch/z80/src/common/up_stackdump.c b/arch/z80/src/common/up_stackdump.c
index dc19f76ed8f..32a3fc68302 100644
--- a/arch/z80/src/common/up_stackdump.c
+++ b/arch/z80/src/common/up_stackdump.c
@@ -78,7 +78,7 @@
 
 static void up_stackdump(void)
 {
-  struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
+  struct tcb_s *rtcb = this_task();
   uint16_t sp = up_getsp();
   uint16_t stack_base = (uint16_t)rtcb->adj_stack_ptr;
   uint16_t stack_size = (uint16_t)rtcb->adj_stack_size;
diff --git a/arch/z80/src/common/up_unblocktask.c b/arch/z80/src/common/up_unblocktask.c
index c0ad48ecac5..f110172052b 100644
--- a/arch/z80/src/common/up_unblocktask.c
+++ b/arch/z80/src/common/up_unblocktask.c
@@ -74,7 +74,7 @@
 
 void up_unblock_task(FAR struct tcb_s *tcb)
 {
-  FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
+  FAR struct tcb_s *rtcb = this_task();
 
   /* Verify that the context switch can be performed */
 
@@ -88,7 +88,7 @@ void up_unblock_task(FAR struct tcb_s *tcb)
   sched_removeblocked(tcb);
 
   /* Add the task in the correct location in the prioritized
-   * g_readytorun task list
+   * ready-to-run task list
    */
 
   if (sched_addreadytorun(tcb))
@@ -112,10 +112,10 @@ void up_unblock_task(FAR struct tcb_s *tcb)
           SAVE_IRQCONTEXT(rtcb);
 
           /* Restore the exception context of the rtcb at the (new) head
-           * of the g_readytorun task list.
+           * of the ready-to-run task list.
            */
 
-          rtcb = (FAR struct tcb_s*)g_readytorun.head;
+          rtcb = this_task();
 
           /* Update scheduler parameters */
 
@@ -139,10 +139,10 @@ void up_unblock_task(FAR struct tcb_s *tcb)
         {
           /* Restore the exception context of the new task that is ready to
            * run (probably tcb).  This is the new rtcb at the head of the
-           * g_readytorun task list.
+           * ready-to-run task list.
            */
 
-          rtcb = (FAR struct tcb_s*)g_readytorun.head;
+          rtcb = this_task();
 
 #ifdef CONFIG_ARCH_ADDRENV
          /* Make sure that the address environment for the previously
diff --git a/arch/z80/src/ez80/ez80_schedulesigaction.c b/arch/z80/src/ez80/ez80_schedulesigaction.c
index b98e61701fa..05e634558b7 100644
--- a/arch/z80/src/ez80/ez80_schedulesigaction.c
+++ b/arch/z80/src/ez80/ez80_schedulesigaction.c
@@ -139,7 +139,7 @@ void up_schedule_sigaction(FAR struct tcb_s *tcb, sig_deliver_t sigdeliver)
        * to the currently executing task.
        */
 
-      if (tcb == (FAR struct tcb_s*)g_readytorun.head)
+      if (tcb == this_task())
         {
           /* CASE 1:  We are not in an interrupt handler and a task is
            * signalling itself for some reason.
diff --git a/arch/z80/src/ez80/ez80_sigdeliver.c b/arch/z80/src/ez80/ez80_sigdeliver.c
index 12db8846aa7..cbd1ad223d8 100644
--- a/arch/z80/src/ez80/ez80_sigdeliver.c
+++ b/arch/z80/src/ez80/ez80_sigdeliver.c
@@ -82,7 +82,7 @@
 void up_sigdeliver(void)
 {
 #ifndef CONFIG_DISABLE_SIGNALS
-  FAR struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
+  FAR struct tcb_s *rtcb = this_task();
   chipreg_t regs[XCPTCONTEXT_REGS];
   sig_deliver_t sigdeliver;
 
diff --git a/arch/z80/src/z180/z180_schedulesigaction.c b/arch/z80/src/z180/z180_schedulesigaction.c
index e212bf0ff8f..1ae1af9627f 100644
--- a/arch/z80/src/z180/z180_schedulesigaction.c
+++ b/arch/z80/src/z180/z180_schedulesigaction.c
@@ -139,7 +139,7 @@ void up_schedule_sigaction(FAR struct tcb_s *tcb, sig_deliver_t sigdeliver)
        * to the currently executing task.
        */
 
-      if (tcb == (FAR struct tcb_s*)g_readytorun.head)
+      if (tcb == this_task())
         {
           /* CASE 1:  We are not in an interrupt handler and a task is
            * signalling itself for some reason.
diff --git a/arch/z80/src/z180/z180_sigdeliver.c b/arch/z80/src/z180/z180_sigdeliver.c
index 58e9aa9c949..076435270d4 100644
--- a/arch/z80/src/z180/z180_sigdeliver.c
+++ b/arch/z80/src/z180/z180_sigdeliver.c
@@ -81,7 +81,7 @@
 void up_sigdeliver(void)
 {
 #ifndef CONFIG_DISABLE_SIGNALS
-  FAR struct tcb_s  *rtcb = (struct tcb_s*)g_readytorun.head;
+  FAR struct tcb_s  *rtcb = this_task();
   chipreg_t regs[XCPTCONTEXT_REGS];
   sig_deliver_t sigdeliver;
 
diff --git a/arch/z80/src/z8/z8_schedulesigaction.c b/arch/z80/src/z8/z8_schedulesigaction.c
index 8d876a52c50..633bdc8bb6e 100644
--- a/arch/z80/src/z8/z8_schedulesigaction.c
+++ b/arch/z80/src/z8/z8_schedulesigaction.c
@@ -139,7 +139,7 @@ void up_schedule_sigaction(FAR struct tcb_s *tcb, sig_deliver_t sigdeliver)
        * to the currently executing task.
        */
 
-      if (tcb == (FAR struct tcb_s*)g_readytorun.head)
+      if (tcb == this_task())
         {
           /* CASE 1:  We are not in an interrupt handler and a task is
            * signalling itself for some reason.
diff --git a/arch/z80/src/z8/z8_sigdeliver.c b/arch/z80/src/z8/z8_sigdeliver.c
index 6605bba7d5e..5101da26928 100644
--- a/arch/z80/src/z8/z8_sigdeliver.c
+++ b/arch/z80/src/z8/z8_sigdeliver.c
@@ -96,7 +96,7 @@ static void z8_copystate(FAR chipreg_t *dest, FAR const chipreg_t *src)
 void up_sigdeliver(void)
 {
 #ifndef CONFIG_DISABLE_SIGNALS
-  FAR struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
+  FAR struct tcb_s *rtcb = this_task();
   chipreg_t regs[XCPTCONTEXT_REGS];
   sig_deliver_t sigdeliver;
 
diff --git a/arch/z80/src/z80/z80_schedulesigaction.c b/arch/z80/src/z80/z80_schedulesigaction.c
index f4581314db8..2f11c7e1143 100644
--- a/arch/z80/src/z80/z80_schedulesigaction.c
+++ b/arch/z80/src/z80/z80_schedulesigaction.c
@@ -139,7 +139,7 @@ void up_schedule_sigaction(FAR struct tcb_s *tcb, sig_deliver_t sigdeliver)
        * to the currently executing task.
        */
 
-      if (tcb == (FAR struct tcb_s*)g_readytorun.head)
+      if (tcb == this_task())
         {
           /* CASE 1:  We are not in an interrupt handler and a task is
            * signalling itself for some reason.
diff --git a/arch/z80/src/z80/z80_sigdeliver.c b/arch/z80/src/z80/z80_sigdeliver.c
index 4e6dafc0bdc..3de591ce4cf 100644
--- a/arch/z80/src/z80/z80_sigdeliver.c
+++ b/arch/z80/src/z80/z80_sigdeliver.c
@@ -81,7 +81,7 @@
 void up_sigdeliver(void)
 {
 #ifndef CONFIG_DISABLE_SIGNALS
-  FAR struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
+  FAR struct tcb_s *rtcb = this_task();
   chipreg_t regs[XCPTCONTEXT_REGS];
   sig_deliver_t sigdeliver;