--- /dev/null
+/*
+ * x86 port IO routines
+ * Copyright (c) 2001, David H. Hovemeyer <daveho@cs.umd.edu>
+ * $Revision: 1.2 $
+ *
+ * This is free software. You are permitted to use,
+ * redistribute, and modify it as specified in the file "COPYING".
+ */
+
+#include <geekos/io.h>
+
+/*
+ * Write a byte to an I/O port.
+ */
+void Out_Byte(ushort_t port, uchar_t value)
+{
+ __asm__ __volatile__ (
+ "outb %b0, %w1"
+ :
+ : "a" (value), "Nd" (port)
+ );
+}
+
+/*
+ * Read a byte from an I/O port.
+ */
+uchar_t In_Byte(ushort_t port)
+{
+ uchar_t value;
+
+ __asm__ __volatile__ (
+ "inb %w1, %b0"
+ : "=a" (value)
+ : "Nd" (port)
+ );
+
+ return value;
+}
+
+/*
+ * Write a word to an I/O port.
+ */
+void Out_Word(ushort_t port, ushort_t value)
+{
+ __asm__ __volatile__ (
+ "outw %w0, %w1"
+ :
+ : "a" (value), "Nd" (port)
+ );
+}
+
+/*
+ * Read a word from an I/O port.
+ */
+ushort_t In_Word(ushort_t port)
+{
+ ushort_t value;
+
+ __asm__ __volatile__ (
+ "inw %w1, %w0"
+ : "=a" (value)
+ : "Nd" (port)
+ );
+
+ return value;
+}
+
+/*
+ * Write a double word to an I/O port.
+ */
+void Out_DWord(ushort_t port, uint_t value)
+{
+ __asm__ __volatile__ (
+ "outl %0, %1"
+ :
+ : "a" (value), "Nd" (port)
+ );
+}
+
+/*
+ * Read a double word from an I/O port.
+ */
+uint_t In_DWord(ushort_t port)
+{
+ uint_t value;
+
+ __asm__ __volatile__ (
+ "inl %1, %0"
+ : "=a" (value)
+ : "Nd" (port)
+ );
+
+ return value;
+}
+
+/*
+ * Short delay. May be needed when talking to some
+ * (slow) I/O devices.
+ */
+void IO_Delay(void)
+{
+ uchar_t value = 0;
+ __asm__ __volatile__ (
+ "outb %0, $0x80"
+ :
+ : "a" (value)
+ );
+}