Make timer interrupt display things on screen

rust_experiments/src/lib.rs

@@ -24,27 +24,27 @@ pub extern fn rust_handle_keyboard() {
     checkerboard(vga_buffer::Color::Green);
 }
 
+static mut timer_count: u64 = 0;
+
 #[no_mangle]
 pub extern fn rust_handle_timer() {
-    let color_code = vga_buffer::ColorCode::new(vga_buffer::Color::Black,
-                                          vga_buffer::Color::White);
+    unsafe {
+        timer_count += 1;
+    }
+    let tc = unsafe { timer_count };
 
+    vga_buffer::print_u32(tc as u32, 23);
 
-    vga_buffer::write_to_coord(40, 1, b'X', color_code);
+    if (tc % 10) == 0 {
+        vga_buffer::print_u32(tc as u32, 24);
+    }
 
 }
 
 #[no_mangle]
 pub extern fn rust_main() {
     clear();
-
     checkerboard(vga_buffer::Color::Red);
-    unsafe {
-        let a = asm_printchar();
-        if a == 1 {
-            checkerboard(vga_buffer::Color::Blue);
-        }
-    }
 
     let mut cur_checkerboard = vga_buffer::Color::Red;
     let mut update_checkerboard = move || {
@@ -55,36 +55,9 @@ pub extern fn rust_main() {
         checkerboard(cur_checkerboard);
     };
 
-    let mut timer;
-    let mut prev_timer = 0;
-
-    let mut count: u32 = 0;
     loop {
-        timer = unsafe { get_rdtsc() };
-        let color_code = vga_buffer::ColorCode::new(vga_buffer::Color::White, vga_buffer::Color::Black);
-        if timer - prev_timer > 4_000_000_000 {
-            update_checkerboard();
 
-            let s = util::u32_to_chars(timer);
-            vga_buffer::print_array(s, 10, color_code); 
-
-            vga_buffer::print_array(
-                util::u32_to_chars(count), 11, color_code);
-            count += 1;
-
-            timer = 0;
-        }
-
-        /*
-        if count > 200 && count % 3 == 0 {
-            unsafe {
-                call_interrupt();
-            }
-        }
-        */
     }
-
-    loop {}
 }
 
 fn clear() {
@@ -152,8 +125,6 @@ mod util {
     }
 }
 
-
-
 mod vga_buffer {
     #[repr(u8)]
     #[derive(Clone, Copy)]
@@ -219,6 +190,12 @@ mod vga_buffer {
         }
     }
 
+    pub fn print_u32(num: u32, location: usize) {
+        let default_color = ColorCode::new(Color::Black, Color::White);
+        let char_array = ::util::u32_to_chars(num);
+        print_array(char_array, location, default_color);
+    }
+
     pub fn write_to_coord(x: usize, y: usize, character: u8, color_code: ColorCode) {
         let ptr = BUFFER_PTR + (2*x as usize) + (BUFFER_WIDTH*2*y as usize);
         let data = ScreenChar {