diff --git a/BOOT/ENVIRON/INC/efidevp.h b/BOOT/ENVIRON/INC/efidevp.h
index 33a585f..ea1ed34 100644
--- a/BOOT/ENVIRON/INC/efidevp.h
+++ b/BOOT/ENVIRON/INC/efidevp.h
@@ -21,8 +21,150 @@ typedef struct _EFI_DEVICE_PATH_PROTOCOL {
     UINT8 SubType;
     UINT8 Length[2];
 } EFI_DEVICE_PATH_PROTOCOL;
-
 typedef struct _EFI_DEVICE_PATH_PROTOCOL _EFI_DEVICE_PATH;
 typedef EFI_DEVICE_PATH_PROTOCOL EFI_DEVICE_PATH;
 
+#define MEDIA_DEVICE_PATH 0x04
+
+#define MEDIA_CDROM_DP 0x02
+
+typedef struct {
+    EFI_DEVICE_PATH Header;
+    UINT32 BootEntry;
+    UINT64 PartitionStart;
+    UINT64 PartitionSize;
+} CDROM_DEVICE_PATH;
+
+FORCEINLINE
+UINT8
+DevicePathType (
+    IN CONST VOID *Node
+    )
+
+/*++
+
+Routine Description:
+
+    Gets the type of a device path node.
+
+Arguments:
+
+    Node - The node to get the type from.
+
+Return Value:
+
+    The type of the node.
+
+--*/
+
+{
+    return ((EFI_DEVICE_PATH *)(Node))->Type;
+}
+
+FORCEINLINE
+UINT8
+DevicePathSubType (
+    IN CONST VOID *Node
+    )
+
+/*++
+
+Routine Description:
+
+    Gets the subtype of a device path node.
+
+Arguments:
+
+    Node - The node to get the subtype from.
+
+Return Value:
+
+    The subtype of the node.
+
+--*/
+
+{
+    return ((EFI_DEVICE_PATH *)(Node))->SubType;
+}
+
+FORCEINLINE
+UINTN
+DevicePathNodeLength (
+    IN CONST VOID *Node
+    )
+
+/*++
+
+Routine Description:
+
+    Gets the length of a device path node.
+
+Arguments:
+
+    Node - The node to get the length from.
+
+Return Value:
+
+    The length of the node.
+
+--*/
+
+{
+    return *((UINT16 *)&((EFI_DEVICE_PATH *)(Node))->Length[0]);
+}
+
+FORCEINLINE
+EFI_DEVICE_PATH *
+NextDevicePathNode (
+    IN CONST VOID *Node
+    )
+
+/*++
+
+Routine Description:
+
+    Finds the next node in a device path.
+
+Arguments:
+
+    Node - The current node to find the next node from.
+
+Return Value:
+
+    A pointer to the next node.
+
+--*/
+
+{
+    return (EFI_DEVICE_PATH *)((UINT8 *)(Node) + DevicePathNodeLength(Node));
+}
+
+FORCEINLINE
+BOOLEAN
+IsDevicePathEndType (
+    IN CONST VOID *Node
+    )
+
+/*++
+
+Routine Description:
+
+    Checks if a device path node is an end node.
+
+Arguments:
+
+    Node - The node to check.
+
+Return Value:
+
+    TRUE if the node is an end node.
+
+    FALSE if the node is not an end node.
+
+--*/
+
+{
+    return (BOOLEAN)(DevicePathType(Node) == END_DEVICE_PATH_TYPE);
+}
+
 #endif