1 files changed, 56 insertions, 0 deletions
diff --git a/mirai/asm/io/port.zig b/mirai/asm/io/port.zig
new file mode 100644
index 0000000..4c2ffbb
--- /dev/null
+++ b/mirai/asm/io/port.zig
@@ -0,0 +1,56 @@
+//! Port I/O Operations
+
+pub fn read_byte(port: u16) u8 {
+    var result: u8 = undefined;
+    asm volatile ("inb %[port], %[result]"
+        : [result] "={al}" (result),
+        : [port] "N{dx}" (port),
+    );
+    return result;
+}
+
+pub fn write_byte(port: u16, value: u8) void {
+    asm volatile ("outb %[value], %[port]"
+        :
+        : [value] "{al}" (value),
+          [port] "N{dx}" (port),
+    );
+}
+
+pub fn read_word(port: u16) u16 {
+    var result: u16 = undefined;
+    asm volatile ("inw %[port], %[result]"
+        : [result] "={ax}" (result),
+        : [port] "N{dx}" (port),
+    );
+    return result;
+}
+
+pub fn write_word(port: u16, value: u16) void {
+    asm volatile ("outw %[value], %[port]"
+        :
+        : [value] "{ax}" (value),
+          [port] "N{dx}" (port),
+    );
+}
+
+pub fn read_long(port: u16) u32 {
+    var result: u32 = undefined;
+    asm volatile ("inl %[port], %[result]"
+        : [result] "={eax}" (result),
+        : [port] "N{dx}" (port),
+    );
+    return result;
+}
+
+pub fn write_long(port: u16, value: u32) void {
+    asm volatile ("outl %[value], %[port]"
+        :
+        : [value] "{eax}" (value),
+          [port] "N{dx}" (port),
+    );
+}
+
+pub fn io_wait() void {
+    write_byte(0x80, 0);
+}