diff --git a/arch/x86/core/ia32/crt0.S b/arch/x86/core/ia32/crt0.S
index e611c884274..c5ea161baf4 100644
--- a/arch/x86/core/ia32/crt0.S
+++ b/arch/x86/core/ia32/crt0.S
@@ -236,6 +236,9 @@ __csSet:
 	lidt	z_x86_idt		/* load 32-bit operand size IDT */
 
 #ifdef CONFIG_LOAPIC
+	/* For BSP, cpu_number is 0 */
+	xorl	%eax, %eax
+	pushl	%eax
 	call	z_loapic_enable
 #endif
 
diff --git a/arch/x86/core/intel64/cpu.c b/arch/x86/core/intel64/cpu.c
index 293c9954e8f..44d44a2ce06 100644
--- a/arch/x86/core/intel64/cpu.c
+++ b/arch/x86/core/intel64/cpu.c
@@ -144,7 +144,8 @@ FUNC_NORETURN void z_x86_cpu_init(struct x86_cpuboot *cpuboot)
 {
 	x86_sse_init(NULL);
 
-	z_loapic_enable();
+	/* The internal cpu_number is the index to x86_cpuboot[] */
+	z_loapic_enable((unsigned char)(cpuboot - x86_cpuboot));
 
 #ifdef CONFIG_USERSPACE
 	/* Set landing site for 'syscall' instruction */
diff --git a/drivers/interrupt_controller/intc_loapic.c b/drivers/interrupt_controller/intc_loapic.c
index 51991ab056f..c2a425c1581 100644
--- a/drivers/interrupt_controller/intc_loapic.c
+++ b/drivers/interrupt_controller/intc_loapic.c
@@ -71,10 +71,27 @@ static u32_t loapic_device_power_state = DEVICE_PM_ACTIVE_STATE;
  * Called from early assembly layer (e.g., crt0.S).
  */
 
-void z_loapic_enable(void)
+void z_loapic_enable(unsigned char cpu_number)
 {
 	s32_t loApicMaxLvt; /* local APIC Max LVT */
 
+#ifndef CONFIG_X2APIC
+	/*
+	 * in xAPIC and flat model, bits 24-31 in LDR (Logical APIC ID) are
+	 * bitmap of target logical APIC ID and it supports maximum 8 local
+	 * APICs.
+	 *
+	 * The logical APIC ID could be arbitrarily selected by system software
+	 * and is different from local APIC ID in local APIC ID register.
+	 *
+	 * We choose 0 for BSP, and the index to x86_cpuboot[] for secondary
+	 * CPUs.
+	 *
+	 * in X2APIC, LDR is read-only.
+	 */
+	x86_write_xapic(LOAPIC_LDR, 1 << (cpu_number + 24));
+#endif
+
 	/*
 	 * enable the local APIC. note that we use xAPIC mode here, since
 	 * x2APIC access is not enabled until the next step (if at all).
@@ -99,6 +116,7 @@ void z_loapic_enable(void)
 	/* reset the DFR, TPR, TIMER_CONFIG, and TIMER_ICR */
 
 #ifndef CONFIG_X2APIC
+	/* Flat model */
 	x86_write_loapic(LOAPIC_DFR, 0xffffffff);  /* no DFR in x2APIC mode */
 #endif
 
diff --git a/include/drivers/interrupt_controller/loapic.h b/include/drivers/interrupt_controller/loapic.h
index 59093408b24..5fbe0662230 100644
--- a/include/drivers/interrupt_controller/loapic.h
+++ b/include/drivers/interrupt_controller/loapic.h
@@ -54,7 +54,7 @@
 extern "C" {
 #endif
 
-extern void z_loapic_enable(void);
+extern void z_loapic_enable(unsigned char cpu_number);
 extern void z_loapic_int_vec_set(unsigned int irq, unsigned int vector);
 extern void z_loapic_irq_enable(unsigned int irq);
 extern void z_loapic_irq_disable(unsigned int irq);