--- linux-3.5.4/arch/x86/kernel/acpi/boot.c	2012-11-05 06:02:54.660816905 +0000
+++ linux-3.5.4.rasm/arch/x86/kernel/acpi/boot.c	2012-11-05 06:02:16.044145822 +0000
@@ -1586,8 +1586,31 @@
 	if (!arg)
 		return -EINVAL;
 
+	/*
+	This hack uses RTC Alarm Hour register to signal if we
+	should enable ACPI or not. This is used to overcome a bug in
+	Kontron pITX-SP and IO-APIC, where we need to boot the
+	kernel without ACPI, reboot and then enable ACPI.
+	*/
+	if (strcmp(arg, "hack") == 0)
+	{
+		outb(0x05 | 0x80, 0x70);
+		if (inb(0x71) == 1)
+		{
+			outb(0x05 | 0x80, 0x70);
+			outb(0x00, 0x71);
+			printk(KERN_WARNING "ACPI: overriding acpi=off\n");
+		}
+		else
+		{
+			outb(0x05 | 0x80, 0x70);
+			outb(0x01, 0x71);
+			printk(KERN_WARNING "ACPI: reboot needed\n");
+			disable_acpi();
+		}
+	}
 	/* "acpi=off" disables both ACPI table parsing and interpreter */
-	if (strcmp(arg, "off") == 0) {
+	else if (strcmp(arg, "off") == 0) {
 		disable_acpi();
 	}
 	/* acpi=force to over-ride black-list */