zephyr: cpu: secondary core idle thread init

Idle thread should be initialize only when core it booting for the first
time. Doing this again would overwrite the kernel structs and the idle
thread stack.

Signed-off-by: Tomasz Leman <tomasz.m.leman@intel.com>

Author: tmleman

zephyr/lib/cpu.c

@@ -79,7 +79,13 @@ int cpu_enable_core(int id)
 		return 0;
 
 #if ZEPHYR_VERSION(3, 0, 99) <= ZEPHYR_VERSION_CODE
-	z_init_cpu(id);
+	/* During kernel initialization, the next pm state is set to ACTIVE. By checking this
+	 * value, we determine if this is the first core boot, if not, we need to skip idle thread
+	 * initialization. By reinitializing the idle thread, we would overwrite the kernel structs
+	 * and the idle thread stack.
+	 */
+	if (pm_state_next_get(id)->state == PM_STATE_ACTIVE)
+		z_init_cpu(id);
 #endif
 
 	atomic_clear(&start_flag);