diff --git a/xtoskrnl/includes/hl.h b/xtoskrnl/includes/hl.h
index 5787ed9..7e55916 100644
--- a/xtoskrnl/includes/hl.h
+++ b/xtoskrnl/includes/hl.h
@@ -23,6 +23,11 @@ HlComPortGetByte(IN PCPPORT Port,
                  IN BOOLEAN Wait,
                  IN BOOLEAN Poll);
 
+XTCDECL
+XTSTATUS
+HlComPortPutByte(IN PCPPORT Port,
+                 IN UCHAR Byte);
+
 XTCDECL
 UCHAR
 HlComPortReadLsr(IN PCPPORT Port,
@@ -34,6 +39,13 @@ HlDrawPixel(IN ULONG PosX,
             IN ULONG PosY,
             IN ULONG Color);
 
+XTCDECL
+XTSTATUS
+HlInitializeComPort(IN OUT PCPPORT Port,
+                    IN ULONG PortNumber,
+                    IN PUCHAR PortAddress,
+                    IN ULONG BaudRate);
+
 XTAPI
 XTSTATUS
 HlInitializeDisplay(VOID);