diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 985b8a8..6979186 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -164,6 +164,24 @@
    -------------------------------------------------------------------------- */
 
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
+int __weak acpi_map_cpu(acpi_handle handle,
+		phys_cpuid_t physid, int *pcpu)
+{
+	return -ENODEV;
+}
+
+int __weak acpi_unmap_cpu(int cpu)
+{
+	return -ENODEV;
+}
+
+int __weak arch_register_cpu(int cpu)
+{
+	return -ENODEV;
+}
+
+void __weak arch_unregister_cpu(int cpu) {}
+
 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 {
 	unsigned long long sta;