*     Activate the first processor.
  */
 
+static void __init boot_cpu_init(void)
+{
+       int cpu = smp_processor_id();
+       /* Mark the boot cpu "present", "online" etc for SMP and UP case */
+       cpu_set(cpu, cpu_online_map);
+       cpu_set(cpu, cpu_present_map);
+       cpu_set(cpu, cpu_possible_map);
+}
+
 asmlinkage void __init start_kernel(void)
 {
        char * command_line;
  * enable them
  */
        lock_kernel();
+       boot_cpu_init();
        page_address_init();
        printk(KERN_NOTICE);
        printk(linux_banner);
        setup_arch(&command_line);
        setup_per_cpu_areas();
-
-       /*
-        * Mark the boot cpu "online" so that it can call console drivers in
-        * printk() and can access its per-cpu storage.
-        */
-       smp_prepare_boot_cpu();
+       smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 
        /*
         * Set up the scheduler prior starting any interrupts (such as the