Remove micromath dependency, improve primitive drawing speed by 300x,

add mouse support and interrupts on x86_64 using a ps2 mouse which
needed pic unmasking, add span filling to framebuffer, add back
without_interrupts to serial console and framebuffer, add a mouse
rectangle which tracks the mouse position and test the performance of
the drawing.

kernel/src/driver/serial.rs

@@ -73,8 +73,10 @@ pub fn init_serial_console(start_x: usize, start_y: usize) {
 }
 
 pub fn with_serial_console<F: FnOnce(&mut SerialConsole)>(f: F) {
-    let mut guard = SERIAL_CONSOLE.lock();
-    if let Some(fb) = guard.as_mut() {
-        f(fb);
-    }
+    without_interrupts(|| {
+        let mut guard = SERIAL_CONSOLE.lock();
+        if let Some(fb) = guard.as_mut() {
+            f(fb);
+        }
+    });
 }