diff --git a/sys/dev/pci.c b/sys/dev/pci.c
index 7234804..b6a43d2 100644
--- a/sys/dev/pci.c
+++ b/sys/dev/pci.c
@@ -6,6 +6,20 @@
 
 void PCI_ScanBus();
 
+// Platform functions
+uint8_t PCICfgRead8(uint32_t bus, uint32_t slot, uint32_t func, uint32_t reg);
+uint16_t PCICfgRead16(uint32_t bus, uint32_t slot, uint32_t func, uint32_t reg);
+uint32_t PCICfgRead32(uint32_t bus, uint32_t slot, uint32_t func, uint32_t reg);
+void PCICfgWrite8(uint32_t bus, uint32_t slot, uint32_t func,
+		  uint32_t reg, uint8_t data);
+void PCICfgWrite16(uint32_t bus, uint32_t slot, uint32_t func,
+		  uint32_t reg, uint16_t data);
+void PCICfgWrite32(uint32_t bus, uint32_t slot, uint32_t func,
+		  uint32_t reg, uint32_t data);
+
+// Supported Devices
+void AHCI_Init(uint32_t bus, uint32_t device, uint32_t func);
+
 void
 PCI_Init()
 {