diff --git a/common_smp/inc/tx_thread.h b/common_smp/inc/tx_thread.h
index b92ce50e6..64998a694 100644
--- a/common_smp/inc/tx_thread.h
+++ b/common_smp/inc/tx_thread.h
@@ -9,6 +9,7 @@
  * SPDX-License-Identifier: MIT
  **************************************************************************/
 
+// Some portions generated by Copilot (Opus 5).
 
 /**************************************************************************/
 /**************************************************************************/
@@ -1171,6 +1172,11 @@ TX_THREAD       *last_thread;
 TX_THREAD       *thread_remap_list[TX_THREAD_SMP_MAX_CORES];
 
 
+    /* Limit the supplied core maps to the cores that are actually present.  */
+    available_cores =       available_cores & ((ULONG) TX_THREAD_SMP_CORE_MASK);
+    thread_possible_cores = thread_possible_cores & ((ULONG) TX_THREAD_SMP_CORE_MASK);
+    test_possible_cores =   test_possible_cores & ((ULONG) TX_THREAD_SMP_CORE_MASK);
+
     /* Clear the last thread cores in the search.  */
     last_thread_cores =  ((ULONG) 0);
 
@@ -1181,6 +1187,9 @@ TX_THREAD       *thread_remap_list[TX_THREAD_SMP_MAX_CORES];
     queue_first =  ((UINT) 0);
     queue_last =   ((UINT) 0);
 
+    /* Initialize the first core queue entry.  */
+    core_queue[0] =  ((UINT) 0);
+
     /* Build a list of possible cores for this thread to execute on, starting
        with the previously mapped core.  */
     core =  schedule_thread -> tx_thread_smp_core_mapped;
diff --git a/common_smp/src/tx_thread_smp_utilities.c b/common_smp/src/tx_thread_smp_utilities.c
index 833a9aab4..cb31e33a9 100644
--- a/common_smp/src/tx_thread_smp_utilities.c
+++ b/common_smp/src/tx_thread_smp_utilities.c
@@ -9,6 +9,7 @@
  * SPDX-License-Identifier: MIT
  **************************************************************************/
 
+// Some portions generated by Copilot (Opus 5).
 
 /**************************************************************************/
 /**************************************************************************/
@@ -654,6 +655,11 @@ TX_THREAD       *last_thread;
 TX_THREAD       *thread_remap_list[TX_THREAD_SMP_MAX_CORES];
 
 
+    /* Limit the supplied core maps to the cores that are actually present.  */
+    available_cores =       available_cores & ((ULONG) TX_THREAD_SMP_CORE_MASK);
+    thread_possible_cores = thread_possible_cores & ((ULONG) TX_THREAD_SMP_CORE_MASK);
+    test_possible_cores =   test_possible_cores & ((ULONG) TX_THREAD_SMP_CORE_MASK);
+
     /* Clear the last thread cores in the search.  */
     last_thread_cores =  ((ULONG) 0);
 
@@ -664,6 +670,9 @@ TX_THREAD       *thread_remap_list[TX_THREAD_SMP_MAX_CORES];
     queue_first =  ((UINT) 0);
     queue_last =   ((UINT) 0);
 
+    /* Initialize the first core queue entry.  */
+    core_queue[0] =  ((UINT) 0);
+
     /* Build a list of possible cores for this thread to execute on, starting
        with the previously mapped core.  */
     core =  schedule_thread -> tx_thread_smp_core_mapped;