Release 1.0

[palacios.git] / geekos / src / geekos / io.c

diff --git a/geekos/src/geekos/io.c b/geekos/src/geekos/io.c
new file mode 100644 (file)
index 0000000..1310cdc
--- /dev/null
+++ b/geekos/src/geekos/io.c
@@ -0,0 +1,108 @@
+/*
+ * 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)
+    );
+}