Add debug! macro. Modify VGA & Writer

src/arch/x86_64/driver/acpi/mod.rs

@@ -7,7 +7,7 @@ use self::structs::*;
 pub fn find_rdsp() -> Option<*const rsdp> {
 	use util::{Checkable, find_in_memory};
 	let ebda = unsafe { *(0x40E as *const u16) as usize } << 4;
-	println!("EBDA at {:#x}", ebda);
+	debug!("EBDA at {:#x}", ebda);
 	if ebda != 0 {
 		if let Some(addr) = unsafe{ find_in_memory::<rsdp>(ebda as usize, 1024, 4) } {
 			return Some(addr as *const rsdp);

src/arch/x86_64/driver/vga.rs

@@ -40,11 +40,20 @@ impl ColorCode {
 
 #[derive(Debug, Clone, Copy)]
 #[repr(C)]
-struct ScreenChar {
+pub struct ScreenChar {
     ascii_char: u8,
     color_code: ColorCode,
 }
 
+impl ScreenChar {
+    pub const fn new(ascii_char: u8, foreground_color: Color, background_color: Color) -> Self {
+        ScreenChar {
+            ascii_char,
+            color_code: ColorCode::new(foreground_color, background_color)
+        }
+    }
+}
+
 pub const BUFFER_HEIGHT: usize = 25;
 pub const BUFFER_WIDTH: usize = 80;
 
@@ -53,30 +62,19 @@ pub struct VgaBuffer {
 }
 
 impl VgaBuffer {
-    fn clear_row(&mut self, row: usize) {
-        let blank = ScreenChar {
-            ascii_char: b' ',
-            color_code: ColorCode::new(Color::White, Color::Black),
-        };
-        for col in 0..BUFFER_WIDTH {
-            self.chars[row][col].write(blank);
-        }
-    }
     pub fn clear(&mut self) {
-        for i in 0 .. BUFFER_HEIGHT {
-            self.clear_row(i);
+        let blank = ScreenChar::new(b' ', Color::LightGray, Color::Black);
+        for row in 0 .. BUFFER_HEIGHT {
+            for col in 0..BUFFER_WIDTH {
+                self.chars[row][col].write(blank);
+            }
         }
     }
-    pub fn write(&mut self, row: usize, col: usize, byte: u8) {
-        let screen_char = &mut self.chars[row][col];
-        let color_code = screen_char.read().color_code;
-        screen_char.write(ScreenChar {
-            ascii_char: byte,
-            color_code: color_code,
-        });
+    pub fn write(&mut self, row: usize, col: usize, screen_char: ScreenChar) {
+        self.chars[row][col].write(screen_char);
     }
-    pub fn byte_at(&self, row: usize, col: usize) -> u8 {
-        self.chars[row][col].read().ascii_char
+    pub fn read(&self, row: usize, col: usize) -> ScreenChar {
+        self.chars[row][col].read()
     }
     pub fn set_cursor_at(&self, row: usize, col: usize) {
         assert!(row < BUFFER_HEIGHT && col < BUFFER_WIDTH);
@@ -97,6 +95,6 @@ mod test {
     fn print_something() {
         let vga = unsafe {&mut *VGA_BUFFER};
         vga.clear();
-        vga.write(0, 0, b'a');
+        vga.write(0, 0, ScreenChar::new('h', Color::LightGray, Color::Black));
     }
 }

src/io/mod.rs

@@ -2,6 +2,17 @@ use core::fmt;
 
 mod vga_writer;
 
+macro_rules! _debug {
+    ($($arg:tt)*) => ({
+        $crate::io::debug(format_args!($($arg)*));
+    });
+}
+
+macro_rules! debug {
+    ($fmt:expr) => (_debug!(concat!($fmt, "\n")));
+    ($fmt:expr, $($arg:tt)*) => (_debug!(concat!($fmt, "\n"), $($arg)*));
+}
+
 macro_rules! print {
     ($($arg:tt)*) => ({
         $crate::io::print(format_args!($($arg)*));
@@ -13,9 +24,22 @@ macro_rules! println {
     ($fmt:expr, $($arg:tt)*) => (print!(concat!($fmt, "\n"), $($arg)*));
 }
 
-pub fn print(args: fmt::Arguments) {
+use arch::driver::vga::Color;
+
+fn print_in_color(args: fmt::Arguments, color: Color) {
     use core::fmt::Write;
-    vga_writer::VGA_WRITER.lock().write_fmt(args).unwrap();
+    use arch::driver::vga::*;    
+    let mut writer = vga_writer::VGA_WRITER.lock();
+    writer.set_color(color);    
+    writer.write_fmt(args).unwrap();
+}
+
+pub fn print(args: fmt::Arguments) {
+    print_in_color(args, Color::LightGray);
+}
+
+pub fn debug(args: fmt::Arguments) {
+    print_in_color(args, Color::LightRed);
 }
 
 pub fn init() {

src/io/vga_writer.rs

@@ -20,11 +20,15 @@ impl VgaWriter {
 		buffer.clear();
 		VgaWriter {
 			column_position: 0,
-			color: Color::White,
+			color: Color::LightGray,
 			buffer: buffer,
 		}
 	}
 
+    pub fn set_color(&mut self, color: Color) {
+        self.color = color;
+    }
+
     pub fn write_byte(&mut self, byte: u8) {
         match byte {
             b'\n' => self.new_line(),
@@ -36,7 +40,7 @@ impl VgaWriter {
                 let row = BUFFER_HEIGHT - 1;
                 let col = self.column_position;
 
-				self.buffer.write(row, col, byte);
+				self.buffer.write(row, col, ScreenChar::new(byte, self.color, Color::Black));
                 self.column_position += 1;
                 self.buffer.set_cursor_at(row, col);
             }
@@ -46,14 +50,16 @@ impl VgaWriter {
     fn new_line(&mut self) {
         for row in 1..BUFFER_HEIGHT {
             for col in 0..BUFFER_WIDTH {
-				let byte = self.buffer.byte_at(row, col);
-				self.buffer.write(row-1, col, byte);
+				let screen_char = self.buffer.read(row, col);
+				self.buffer.write(row-1, col, screen_char);
             }
         }
+        let blank = ScreenChar::new(b' ', self.color, Color::Black);        
 		for col in 0..BUFFER_WIDTH {
-			self.buffer.write(BUFFER_HEIGHT-1, col, b' ');
+			self.buffer.write(BUFFER_HEIGHT-1, col, blank);
 		}
         self.column_position = 0;
+        self.buffer.set_cursor_at(BUFFER_HEIGHT-1, 0);
     }
 }