-#define IOAPIC_REG_SEL *((volatile uint32_t*)(MMIO_IOAPIC + IOAPIC_IOREGSEL))
-#define IOAPIC_REG_WIN *((volatile uint32_t*)(MMIO_IOAPIC + IOAPIC_IOWIN))
+#define IOAPIC_REG_SEL *((volatile uint32_t*)(_ioapic_base + IOAPIC_IOREGSEL))
+#define IOAPIC_REG_WIN *((volatile uint32_t*)(_ioapic_base + IOAPIC_IOWIN))
+
+static volatile uintptr_t _ioapic_base;