aarch64/fb: add basic console driver

kernel/src/arch/aarch64/board/raspi3/fb.rs

@@ -175,6 +175,16 @@ impl Framebuffer {
             RGBA8888 => self.buf.write32(y * self.fb_info.xres + x, pixel),
         }
     }
+
+    /// Clean screen
+    pub fn clear(&mut self) {
+        let mut start = self.base_addr();
+        let end = start + self.fb_info.screen_size as usize;
+        while start < end {
+            unsafe { *(start as *mut usize) = 0 }
+            start += core::mem::size_of::<usize>();
+        }
+    }
 }
 
 lazy_static! {
@@ -185,7 +195,6 @@ lazy_static! {
 pub fn init() {
     match Framebuffer::new(0, 0, 0) {
         Ok(fb) => {
-            let info = fb.fb_info;
             info!("framebuffer: init end\n{:#x?}", fb);
             *FRAME_BUFFER.lock() = Some(fb);
         }

kernel/src/arch/aarch64/board/raspi3/serial.rs

@@ -22,7 +22,7 @@ impl SerialPort {
     }
 
     /// Init a newly created SerialPort, can only be called once.
-    pub fn init(&mut self) {
+    fn init(&mut self) {
         assert_has_not_been_called!("SerialPort::init must be called only once");
 
         self.mu.init();

kernel/src/arch/aarch64/driver/console.rs

@@ -0,0 +1,198 @@
+//! Framebuffer console display driver for ARM64
+
+use super::board::fb::{FramebufferInfo, FRAME_BUFFER};
+use alloc::vec::Vec;
+use core::fmt::{self, Write};
+use lazy_static::lazy_static;
+use spin::Mutex;
+
+#[derive(Debug, Clone, Copy)]
+struct Color(u8);
+
+#[derive(Debug, Clone, Copy)]
+#[repr(C)]
+pub struct ConsoleChar {
+    ascii_char: u8,
+    color: Color,
+}
+
+impl Default for ConsoleChar {
+    fn default() -> Self {
+        ConsoleChar {
+            ascii_char: b' ',
+            color: Color(0),
+        }
+    }
+}
+
+const CHAR_WIDTH: u16 = 8;
+const CHAR_HEIGHT: u16 = 16;
+
+/// Character buffer
+struct ConsoleBuffer {
+    num_row: u16,
+    num_col: u16,
+    buf: Vec<Vec<ConsoleChar>>,
+}
+
+impl ConsoleBuffer {
+    fn new(num_row: u16, num_col: u16) -> ConsoleBuffer {
+        ConsoleBuffer {
+            num_row,
+            num_col,
+            buf: vec![vec![ConsoleChar::default(); num_col as usize]; num_row as usize],
+        }
+    }
+
+    /// Read one character at `(row, col)`.
+    fn read(&self, row: u16, col: u16) -> ConsoleChar {
+        self.buf[row as usize][col as usize]
+    }
+
+    /// Write one character at `(row, col)`.
+    /// TODO: font & color
+    fn write(&mut self, row: u16, col: u16, ch: ConsoleChar) {
+        self.buf[row as usize][col as usize] = ch;
+
+        let off_x = col * CHAR_WIDTH;
+        let off_y = row * CHAR_HEIGHT;
+        if let Some(fb) = FRAME_BUFFER.lock().as_mut() {
+            for y in 0..CHAR_HEIGHT {
+                for x in 0..CHAR_WIDTH {
+                    let pixel = if ch.color.0 == 0 { 0 } else { !0 };
+                    fb.write((off_x + x) as u32, (off_y + y) as u32, pixel);
+                }
+            }
+        }
+    }
+
+    /// Delete one character at `(row, col)`.
+    fn delete(&mut self, row: u16, col: u16) {
+        self.write(row, col, ConsoleChar::default());
+    }
+
+    /// Insert one blank line at the bottom and remove the top line.
+    /// TODO: improve performance
+    fn new_line(&mut self) {
+        for i in 1..self.num_row {
+            for j in 0..self.num_col {
+                self.write(i - 1, j, self.read(i, j));
+            }
+        }
+        for j in 0..self.num_col {
+            self.write(self.num_row - 1, j, ConsoleChar::default());
+        }
+    }
+
+    /// Clear the entire buffer and screen.
+    fn clear(&mut self) {
+        for i in 0..self.num_row as usize {
+            for j in 0..self.num_col as usize {
+                self.buf[i][j] = ConsoleChar::default()
+            }
+        }
+        if let Some(fb) = FRAME_BUFFER.lock().as_mut() {
+            fb.clear();
+        }
+    }
+}
+
+/// Console structure
+pub struct Console {
+    /// current color
+    color: Color,
+    /// cursor row
+    row: u16,
+    /// cursor column
+    col: u16,
+    /// number of rows
+    num_row: u16,
+    /// number of columns
+    num_col: u16,
+    /// character buffer
+    buf: ConsoleBuffer,
+}
+
+impl Console {
+    fn new(fb: &FramebufferInfo) -> Console {
+        let num_row = fb.yres as u16 / CHAR_HEIGHT;
+        let num_col = fb.xres as u16 / CHAR_WIDTH;
+        Console {
+            color: Color(1),
+            row: 0,
+            col: 0,
+            num_row,
+            num_col,
+            buf: ConsoleBuffer::new(num_row, num_col),
+        }
+    }
+
+    fn new_line(&mut self) {
+        self.col = 0;
+        if self.row < self.num_row - 1 {
+            self.row += 1;
+        } else {
+            self.buf.new_line();
+        }
+    }
+
+    fn write_byte(&mut self, byte: u8) {
+        match byte {
+            b'\x7f' => {
+                if self.col > 0 {
+                    self.col -= 1;
+                    self.buf.delete(self.row, self.col);
+                } else if self.row > 0 {
+                    self.row -= 1;
+                    self.col = self.num_col - 1;
+                    self.buf.delete(self.row, self.col);
+                }
+            }
+            b'\n' => self.new_line(),
+            b'\r' => self.col = 0,
+            byte => {
+                if self.col >= self.num_col {
+                    self.new_line();
+                }
+
+                let ch = ConsoleChar {
+                    ascii_char: byte,
+                    color: self.color,
+                };
+                self.buf.write(self.row, self.col, ch);
+                self.col += 1;
+            }
+        }
+    }
+
+    pub fn clear(&mut self) {
+        self.color = Color(1);
+        self.row = 0;
+        self.col = 0;
+        self.buf.clear();
+    }
+}
+
+impl fmt::Write for Console {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        for byte in s.bytes() {
+            self.write_byte(byte)
+        }
+        Ok(())
+    }
+}
+
+lazy_static! {
+    pub static ref CONSOLE: Mutex<Option<Console>> = Mutex::new(None);
+}
+
+/// Initialize console driver
+pub fn init() {
+    if let Some(fb) = FRAME_BUFFER.lock().as_ref() {
+        *CONSOLE.lock() = Some(Console::new(&fb.fb_info));
+    }
+
+    if let Some(console) = CONSOLE.lock().as_mut() {
+        console.write_str("Hello Raspberry Pi!\n").unwrap();
+    }
+}

kernel/src/arch/aarch64/driver/mod.rs

@@ -1,12 +1,14 @@
-/// ARM64 drivers
-
-use once::*;
+//! ARM64 drivers
 
 use super::board;
+use once::*;
+
+pub mod console;
 
 /// Initialize ARM64 common drivers
 pub fn init() {
-    assert_has_not_been_called!();
+    assert_has_not_been_called!("driver::init must be called only once");
 
     board::init_driver();
+    console::init();
 }

kernel/src/arch/aarch64/io.rs

@@ -1,14 +1,20 @@
 //! Serial driver for aarch64.
 
-use core::fmt::{Arguments, Write};
 use super::board::serial::*;
+use super::driver::console::CONSOLE;
+use core::fmt::{Arguments, Write};
 
 pub fn getchar() -> char {
-    unsafe { SERIAL_PORT.force_unlock(); }
+    unsafe { SERIAL_PORT.force_unlock() }
     SERIAL_PORT.lock().receive() as char
 }
 
 pub fn putfmt(fmt: Arguments) {
-    unsafe { SERIAL_PORT.force_unlock(); }
-    SERIAL_PORT.lock().write_fmt(fmt).unwrap()
+    unsafe { SERIAL_PORT.force_unlock() }
+    SERIAL_PORT.lock().write_fmt(fmt).unwrap();
+
+    unsafe { CONSOLE.force_unlock() }
+    if let Some(console) = CONSOLE.lock().as_mut() {
+        console.write_fmt(fmt).unwrap();
+    }
 }