+#define IOAPIC_IOREGSEL 0x00
+#define IOAPIC_IOWIN 0x10
+#define IOAPIC_IOREDTBL_BASE 0x10
+
+#define IOAPIC_REG_ID 0x00
+#define IOAPIC_REG_VER 0x01
+#define IOAPIC_REG_ARB 0x02
+
+#define IOAPIC_DELMOD_FIXED 0b000
+#define IOAPIC_DELMOD_LPRIO 0b001
+#define IOAPIC_DELMOD_NMI 0b100
+
+#define IOAPIC_MASKED (1 << 16)
+#define IOAPIC_TRIG_LEVEL (1 << 15)
+#define IOAPIC_INTPOL_L (1 << 13)
+#define IOAPIC_DESTMOD_LOGIC (1 << 11)
+
+#define IOAPIC_BASE_VADDR 0x2000
+
+#define IOAPIC_REG_SEL *((volatile u32_t*)(_ioapic_base + IOAPIC_IOREGSEL))
+#define IOAPIC_REG_WIN *((volatile u32_t*)(_ioapic_base + IOAPIC_IOWIN))
+
+
+#define LVT_ENTRY_LINT0(vector) (LVT_DELIVERY_FIXED | vector)
+
+// Pin LINT#1 is configured for relaying NMI, but we masked it here as I think
+// it is too early for that
+// LINT#1 *must* be edge trigged (Intel manual vol3. 10-14)
+#define LVT_ENTRY_LINT1 (LVT_DELIVERY_NMI | LVT_MASKED | LVT_TRIGGER_EDGE)
+#define LVT_ENTRY_ERROR(vector) (LVT_DELIVERY_FIXED | vector)
+
+
+static volatile ptr_t _ioapic_base;