1 files changed, 23 insertions, 0 deletions
diff --git a/i686/sys/io.h b/i686/sys/io.h
index 74d4950..b6c24c5 100644
--- a/i686/sys/io.h
+++ b/i686/sys/io.h
@@ -1,5 +1,27 @@
 #pragma once
 
+// port listings
+enum UART {
+  COM1 = 0x3f8,
+  COM2 = 0x2f8,
+  COM3 = 0x3e8,
+  COM4 = 0x2e8,
+  COM5 = 0x5f8,
+  COM6 = 0x4f8,
+  COM7 = 0x5e8,
+  COM8 = 0x4e8,
+};
+enum UARTPortOffset {
+  Data = 0,             // read from receive buffer / write to transmit buffer | BaudDiv_l
+  InterruptControl = 1, // interrupt enable | BaudDiv_h
+  FifoControl = 2,      // interrupt ID and FIFO control
+  LineControl = 3,      // most significant bit is the DLAB
+  ModemControl = 4,
+  LineStatus = 5,
+  ModemStatus = 6,
+  Scratch = 7,
+};
+
 static inline void
 outb(unsigned char val, unsigned short port)
 {
@@ -77,3 +99,4 @@ insl(unsigned short port, void *__buf, unsigned long __n)
 {
   asm volatile("cld; rep; insl" : "+D"(__buf), "+c"(__n) : "d"(port));
 }
+