diff --git a/demos/RP/RT-RP2040-PICO/c1_main.c b/demos/RP/RT-RP2040-PICO/c1_main.c
index 21308b892..c8ce9155e 100644
--- a/demos/RP/RT-RP2040-PICO/c1_main.c
+++ b/demos/RP/RT-RP2040-PICO/c1_main.c
@@ -31,41 +31,6 @@ static const ShellConfig shell_cfg1 = {
   commands
 };
 
-/**
- * @brief   Core 1 OS instance.
- */
-os_instance_t ch1;
-
-#if (CH_CFG_NO_IDLE_THREAD == FALSE) || defined(__DOXYGEN__)
-/**
- * @brief   Default instance idle thread working area.
- */
-THD_WORKING_AREA(ch_c1_idle_thread_wa, PORT_IDLE_THREAD_STACK_SIZE);
-#endif
-
-#if CH_DBG_ENABLE_STACK_CHECK == TRUE
-extern stkalign_t __c1_main_thread_stack_base__, __c1_main_thread_stack_end__;
-#endif
-
-/**
- * @brief   Core 1 OS instance configuration.
- */
-static const os_instance_config_t core1_cfg = {
-  .name             = "c1",
-#if CH_DBG_ENABLE_STACK_CHECK == TRUE
-  .mainthread_base  = &__c1_main_thread_stack_base__,
-  .mainthread_end   = &__c1_main_thread_stack_end__,
-#elif CH_CFG_USE_DYNAMIC == TRUE
-  .mainthread_base  = NULL,
-  .mainthread_end   = NULL,
-#endif
-#if CH_CFG_NO_IDLE_THREAD == FALSE
-  .idlethread_base  = THD_WORKING_AREA_BASE(ch_c1_idle_thread_wa),
-  .idlethread_end   = THD_WORKING_AREA_END(ch_c1_idle_thread_wa)
-#endif
-};
-
-
 /*
  * Green LED blinker thread, times are in milliseconds.
  */
@@ -91,7 +56,7 @@ void c1_main(void) {
    * system initialization on the other side.
    */
   chSysWaitSystemState(ch_sys_running);
-  chSchObjectInit(&ch1, &core1_cfg);
+  chSchObjectInit(&ch1, &ch_core1_cfg);
 
   /* It is alive now.*/
   chSysUnlock();
diff --git a/os/rt/include/chsys.h b/os/rt/include/chsys.h
index 627f0bc63..c9838a990 100644
--- a/os/rt/include/chsys.h
+++ b/os/rt/include/chsys.h
@@ -292,10 +292,17 @@
 
 #if !defined(__DOXYGEN__)
 extern ch_system_t ch_system;
+
+extern const os_instance_config_t ch_core0_cfg;
 extern os_instance_t ch0;
-extern stkalign_t ch_idle_thread_wa[];
+
+#if PORT_CORES_NUMBER > 1
+extern const os_instance_config_t ch_core1_cfg;
+extern os_instance_t ch1;
 #endif
 
+#endif /* !defined(__DOXYGEN__) */
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/os/rt/src/chsys.c b/os/rt/src/chsys.c
index d238f4300..6a8a67474 100644
--- a/os/rt/src/chsys.c
+++ b/os/rt/src/chsys.c
@@ -45,17 +45,75 @@
 ch_system_t ch_system;
 
 /**
- * @brief   Default OS instance.
+ * @brief   Core 0 OS instance.
  */
 os_instance_t ch0;
 
 #if (CH_CFG_NO_IDLE_THREAD == FALSE) || defined(__DOXYGEN__)
 /**
- * @brief   Default instance idle thread working area.
+ * @brief   Working area for core 0 idle thread.
  */
-THD_WORKING_AREA(ch_idle_thread_wa, PORT_IDLE_THREAD_STACK_SIZE);
+THD_WORKING_AREA(ch_c0_idle_thread_wa, PORT_IDLE_THREAD_STACK_SIZE);
+
+#if CH_DBG_ENABLE_STACK_CHECK == TRUE
+extern stkalign_t __main_thread_stack_base__, __main_thread_stack_end__;
 #endif
 
+/**
+ * @brief   Core 0 OS instance configuration.
+ */
+const os_instance_config_t ch_core0_cfg = {
+  .name             = "c0",
+#if CH_DBG_ENABLE_STACK_CHECK == TRUE
+  .mainthread_base  = &__main_thread_stack_base__,
+  .mainthread_end   = &__main_thread_stack_end__,
+#elif CH_CFG_USE_DYNAMIC == TRUE
+  .mainthread_base  = NULL,
+  .mainthread_end   = NULL,
+#endif
+#if CH_CFG_NO_IDLE_THREAD == FALSE
+  .idlethread_base  = THD_WORKING_AREA_BASE(ch_c0_idle_thread_wa),
+  .idlethread_end   = THD_WORKING_AREA_END(ch_c0_idle_thread_wa)
+#endif
+};
+#endif
+
+#if (PORT_CORES_NUMBER > 1) || defined(__DOXYGEN__)
+/**
+ * @brief   Core 1 OS instance.
+ */
+os_instance_t ch1;
+
+#if (CH_CFG_NO_IDLE_THREAD == FALSE) || defined(__DOXYGEN__)
+/**
+ * @brief   Working area for core 1 idle thread.
+ */
+THD_WORKING_AREA(ch_c1_idle_thread_wa, PORT_IDLE_THREAD_STACK_SIZE);
+#endif
+
+#if CH_DBG_ENABLE_STACK_CHECK == TRUE
+extern stkalign_t __c1_main_thread_stack_base__, __c1_main_thread_stack_end__;
+#endif
+
+/**
+ * @brief   Core 1 OS instance configuration.
+ */
+const os_instance_config_t ch_core1_cfg = {
+  .name             = "c1",
+#if CH_DBG_ENABLE_STACK_CHECK == TRUE
+  .mainthread_base  = &__c1_main_thread_stack_base__,
+  .mainthread_end   = &__c1_main_thread_stack_end__,
+#elif CH_CFG_USE_DYNAMIC == TRUE
+  .mainthread_base  = NULL,
+  .mainthread_end   = NULL,
+#endif
+#if CH_CFG_NO_IDLE_THREAD == FALSE
+  .idlethread_base  = THD_WORKING_AREA_BASE(ch_c1_idle_thread_wa),
+  .idlethread_end   = THD_WORKING_AREA_END(ch_c1_idle_thread_wa)
+#endif
+};
+#endif /* PORT_CORES_NUMBER > 1 */
+
 /*===========================================================================*/
 /* Module local types.                                                       */
 /*===========================================================================*/
@@ -122,29 +180,7 @@ void chSysInit(void) {
   __oslib_init();
 
   /* Initializing default OS instance.*/
-  {
-#if CH_DBG_ENABLE_STACK_CHECK == TRUE
-    extern stkalign_t __main_thread_stack_base__,
-                      __main_thread_stack_end__;
-#endif
-
-    static const os_instance_config_t default_cfg = {
-      .name             = "c0",
-#if CH_DBG_ENABLE_STACK_CHECK == TRUE
-      .mainthread_base  = &__main_thread_stack_base__,
-      .mainthread_end   = &__main_thread_stack_end__,
-#elif CH_CFG_USE_DYNAMIC == TRUE
-      .mainthread_base  = NULL,
-      .mainthread_end   = NULL,
-#endif
-#if CH_CFG_NO_IDLE_THREAD == FALSE
-      .idlethread_base  = THD_WORKING_AREA_BASE(ch_idle_thread_wa),
-      .idlethread_end   = THD_WORKING_AREA_END(ch_idle_thread_wa)
-#endif
-    };
-
-    chSchObjectInit(&ch0, &default_cfg);
-  }
+  chSchObjectInit(&ch0, &ch_core0_cfg);
 
   /* It is alive now.*/
   ch_system.state = ch_sys_running;