port

kernel/src/x86_64.rs

@@ -12,3 +12,38 @@ pub fn halt_loop() -> ! {
         hlt();
     }
 }
+
+#[repr(transparent)]
+pub struct PortU16(pub u16);
+
+impl PortU16 {
+    pub fn offset(&self, offset: u16) -> Self {
+        Self(self.0 + offset)
+    }
+
+    #[inline]
+    pub unsafe fn read(&self) -> u16 {
+        let value: u16;
+        unsafe {
+            core::arch::asm!(
+                "in ax, dx",
+                in("dx") self.0,
+                out("ax") value,
+                options(nomem, nostack, preserves_flags)
+            );
+        }
+        value
+    }
+
+    #[inline]
+    pub unsafe fn write(&self, value: u16) {
+        unsafe {
+            core::arch::asm!(
+                "out dx, ax",
+                in("dx") self.0,
+                in("ax") value,
+                options(nomem, nostack, preserves_flags)
+            );
+        }
+    }
+}