diff -ruN linux-2.4.21-pre5/arch/i386/kernel/apic.c linux-2.4.21-pre5.apic-fixes/arch/i386/kernel/apic.c
--- linux-2.4.21-pre5/arch/i386/kernel/apic.c	2003-02-27 12:58:55.000000000 +0100
+++ linux-2.4.21-pre5.apic-fixes/arch/i386/kernel/apic.c	2003-02-27 13:05:28.000000000 +0100
@@ -649,7 +649,6 @@
 	}
 	set_bit(X86_FEATURE_APIC, &boot_cpu_data.x86_capability);
 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
-	boot_cpu_physical_apicid = 0;
 	if (nmi_watchdog != NMI_NONE)
 		nmi_watchdog = NMI_LOCAL_APIC;
 
@@ -1169,8 +1168,7 @@
 
 	connect_bsp_APIC();
 
-	phys_cpu_present_map = 1;
-	apic_write_around(APIC_ID, boot_cpu_physical_apicid);
+	phys_cpu_present_map = 1 << boot_cpu_physical_apicid;
 
 	apic_pm_init2();