vga

kernel-rs/README.md

@@ -21,18 +21,9 @@ rustup component add rust-src
 cargo install xargo
 ```
 
-### docker
-a standard development environment can be invoked:
-
-```
-docker run jzck/arch-kernel -it /usr/bin/zsh
-```
-
-clone the repo and `make iso`
-
 # running
 
-`make run` in your host operating system to launch qemu gtk window
+`make run` runs the OS + a tmux split for the qemu terminal
 
 # References
 

kernel-rs/src/lib.rs

@@ -12,8 +12,25 @@ mod vga_buffer;
 
 #[no_mangle]
 pub extern fn kmain() -> ! {
-    vga_buffer::clear_screen();
+    use vga_buffer::WRITER;
-    println!("Kernel startup...");
+    use vga_buffer::Color;
+    use vga_buffer::ColorCode;
+
+    WRITER.lock().reset_screen();
+    println!(">> Kernel startup...");
+    println!(">> Kernel startup...");
+
+    WRITER.lock().color_code = ColorCode::new(Color::Blue, Color::Yellow);
+    println!(">> Kernel startup...");
+    println!(">> Kernel startup...");
+    println!(">> Kernel startup...");
+
+    WRITER.lock().color_code = ColorCode::new(Color::Red, Color::Green);
+    println!(">> Kernel startup...");
+    println!(">> Kernel startup...");
+    println!(">> Kernel startup...");
+
+    WRITER.lock().color_code = ColorCode::new(Color::White, Color::Black);
 
     loop {
         

kernel-rs/src/vga_buffer.rs

@@ -12,26 +12,27 @@ use core::fmt;
 use spin::Mutex;
 use volatile::Volatile;
 
-struct Buffer {
-    chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
-}
-
 const BUFFER_HEIGHT: usize = 25;
 const BUFFER_WIDTH: usize = 80;
 
-static mut VGA_BUFFER: Unique<Buffer> = unsafe {
-    Unique::new_unchecked(0xb8000 as *mut _)
-};
-
-fn vga_buffer() -> &'static mut Buffer {
-    unsafe { VGA_BUFFER.as_mut() }
-}
-
 pub static WRITER: Mutex<Writer> = Mutex::new(Writer {
     column_position: 0,
-    color_code: ColorCode::new(Color::LightGreen, Color::Black),
+    color_code: ColorCode::new(Color::White, Color::Black),
+    vgabuffer: unsafe { Unique::new_unchecked(0xb8000 as *mut _) },
 });
 
+pub struct Writer {
+    column_position: usize,
+    pub color_code: ColorCode,
+    vgabuffer: Unique<Buffer>,
+}
+
+struct VScreen {
+    column_position: usize,
+    pub color_code: ColorCode,
+    buffer: Buffer,
+}
+
 macro_rules! println {
     ($fmt:expr) => (print!(concat!($fmt, "\n")));
     ($fmt:expr, $($arg:tt)*) => (print!(concat!($fmt, "\n"), $($arg)*));
@@ -39,7 +40,7 @@ macro_rules! println {
 
 macro_rules! print {
     ($($arg:tt)*) => ({
-            $crate::vga_buffer::print(format_args!($($arg)*));
+        $crate::vga_buffer::print(format_args!($($arg)*));
     });
 }
 
@@ -48,9 +49,75 @@ pub fn print(args: fmt::Arguments) {
     WRITER.lock().write_fmt(args).unwrap();
 }
 
-pub fn clear_screen() {
+impl Writer {
-    for _ in 0..BUFFER_HEIGHT {
+    pub fn reset_screen(&mut self)
-        println!("");
+    {
+        let color_code = self.color_code;
+        for row in 1..BUFFER_HEIGHT {
+            for col in 0..BUFFER_WIDTH {
+                self.buffer().chars[row][col].write(ScreenChar {
+                    ascii_character: b' ',
+                    color_code,
+                });
+            }
+        }
+        self.column_position = 0;
+    }
+
+    pub fn write_byte(&mut self, byte: u8) {
+        match byte {
+            b'\n' => self.new_line(),
+            byte => {
+                if self.column_position >= BUFFER_WIDTH {
+                    self.new_line();
+                }
+                let row = BUFFER_HEIGHT - 1;
+                let col = self.column_position;
+
+                let color_code = self.color_code;
+
+                self.buffer().chars[row][col].write(ScreenChar {
+                    ascii_character: byte,
+                    color_code: color_code,
+                });
+                self.column_position += 1;
+            }
+        }
+    }
+
+    fn buffer(&mut self) -> &mut Buffer {
+        unsafe { self.vgabuffer.as_mut() }
+    }
+
+    fn new_line(&mut self) {
+        for row in 1..BUFFER_HEIGHT {
+            for col in 0..BUFFER_WIDTH {
+                let buffer = self.buffer();
+                let character = buffer.chars[row][col].read();
+                buffer.chars[row - 1][col].write(character);
+            }
+        }
+        self.clear_row(BUFFER_HEIGHT - 1);
+        self.column_position = 0;
+    }
+
+    fn clear_row(&mut self, row: usize) {
+        let blank = ScreenChar {
+            ascii_character: b' ',
+            color_code: ColorCode::new(Color::White, Color::Black),
+        };
+        for col in 0..BUFFER_WIDTH {
+            self.buffer().chars[row][col].write(blank);
+        }
+    }
+}
+
+impl fmt::Write for Writer {
+    fn write_str(&mut self, s: &str) -> ::core::fmt::Result {
+        for byte in s.bytes() {
+            self.write_byte(byte)
+        }
+        Ok(())
     }
 }
 
@@ -76,70 +143,11 @@ pub enum Color {
     White = 15,
 }
 
-pub struct Writer {
-    column_position: usize,
-    color_code: ColorCode,
-}
-
-impl Writer {
-    pub fn write_byte(&mut self, byte: u8) {
-        match byte {
-            b'\n' => self.new_line(),
-            byte => {
-                if self.column_position >= BUFFER_WIDTH {
-                    self.new_line();
-                }
-                let row = BUFFER_HEIGHT - 1;
-                let col = self.column_position;
-
-                let color_code = self.color_code;
-
-                vga_buffer().chars[row][col].write(ScreenChar {
-                    ascii_character: byte,
-                    color_code: color_code,
-                });
-                self.column_position += 1;
-            }
-        }
-    }
-
-    fn new_line(&mut self) {
-        for row in 1..BUFFER_HEIGHT {
-            for col in 0..BUFFER_WIDTH {
-                let buffer = vga_buffer();
-                let character = buffer.chars[row][col].read();
-                buffer.chars[row - 1][col].write(character);
-            }
-        }
-        self.clear_row(BUFFER_HEIGHT - 1);
-        self.column_position = 0;
-    }
-
-    fn clear_row(&mut self, row: usize) {
-        let blank = ScreenChar {
-            ascii_character: b' ',
-            color_code: self.color_code,
-        };
-        for col in 0..BUFFER_WIDTH {
-            vga_buffer().chars[row][col].write(blank);
-        }
-    }
-}
-
-impl fmt::Write for Writer {
-    fn write_str(&mut self, s: &str) -> ::core::fmt::Result {
-        for byte in s.bytes() {
-            self.write_byte(byte)
-        }
-        Ok(())
-    }
-}
-
 #[derive(Debug, Clone, Copy)]
-struct ColorCode(u8);
+pub struct ColorCode(u8);
 
 impl ColorCode {
-    const fn new(foreground: Color, background: Color) -> ColorCode {
+    pub const fn new(foreground: Color, background: Color) -> ColorCode {
         ColorCode((background as u8) << 4 | (foreground as u8))
     }
 }
@@ -150,3 +158,7 @@ struct ScreenChar {
     ascii_character: u8,
     color_code: ColorCode,
 }
+
+struct Buffer {
+    chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
+}