feat(serial): add external serial driver

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>

Cargo.lock

@@ -2,13 +2,27 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "bit_field"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcb6dd1c2376d2e096796e234a70e17e94cc2d5d54ff8ce42b28cef1d0d359a4"
+
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
 [[package]]
 name = "julios"
 version = "0.1.0"
 dependencies = [
  "lazy_static",
  "spin",
- "volatile",
+ "uart_16550",
+ "volatile 0.2.7",
+ "x86_64",
 ]
 
 [[package]]
@@ -26,8 +40,35 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
 
+[[package]]
+name = "uart_16550"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65ad019480ef5ff8ffe66d6f6a259cd87cf317649481394981db1739d844f374"
+dependencies = [
+ "bitflags",
+ "x86_64",
+]
+
 [[package]]
 name = "volatile"
 version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6b06ad3ed06fef1713569d547cdbdb439eafed76341820fb0e0344f29a41945"
+
+[[package]]
+name = "volatile"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e4c2dbd44eb8b53973357e6e207e370f0c1059990df850aca1eca8947cf464f0"
+
+[[package]]
+name = "x86_64"
+version = "0.14.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbc6ed1ed2cd4536b083c34041aff7b84448ee25ac4aa5e9d54802ce226f9815"
+dependencies = [
+ "bit_field",
+ "bitflags",
+ "volatile 0.4.4",
+]

Cargo.toml

@@ -11,6 +11,8 @@ crate-type = ["staticlib"]
 [dependencies]
 volatile = "0.2.6"
 spin = "0.5.2"
+x86_64 = "0.14.2"
+uart_16550 = "0.2.0"
 
 [dependencies.lazy_static]
 version = "1.0"

Makefile

@@ -12,7 +12,7 @@ GRUB_CFG = grub/grub.cfg
 all: $(ISO)
 
 run: $(ISO)
-	qemu-system-x86_64 -cdrom $<
+	qemu-system-x86_64 -cdrom $< -serial stdio
 
 debug: $(ISO)
 	bochs -q

src/lib.rs

@@ -2,6 +2,7 @@
 #![no_main]
 
 mod vga;
+mod serial;
 use core::panic::PanicInfo;
 use vga::Color;
 
@@ -12,11 +13,10 @@ fn panic_handler(info: &PanicInfo) -> ! {
     loop {}
 }
 
-
 #[no_mangle]
 pub extern "C" fn julios_main() -> ! {
     println!("Hello World!");
     println!("{}", "***JuliOS***");
-    panic!("Test panic");
-    loop {}
+    serial_println!("Test serial");
+    panic!("Kernel end of flow");
 }

src/serial.rs

@@ -0,0 +1,34 @@
+use uart_16550::SerialPort;
+use spin::Mutex;
+use lazy_static::lazy_static;
+
+lazy_static! {
+    pub static ref SERIAL1: Mutex<SerialPort> = {
+        let mut serial_port = unsafe { SerialPort::new(0x3F8) };
+        serial_port.init();
+        Mutex::new(serial_port)
+    };
+}
+
+#[doc(hidden)]
+pub fn _print(args: ::core::fmt::Arguments) {
+    use core::fmt::Write;
+    SERIAL1.lock().write_fmt(args).expect("Printing to serial failed");
+}
+
+/// Prints to the host through the serial interface.
+#[macro_export]
+macro_rules! serial_print {
+    ($($arg:tt)*) => {
+        $crate::serial::_print(format_args!($($arg)*));
+    };
+}
+
+/// Prints to the host through the serial interface, appending a newline.
+#[macro_export]
+macro_rules! serial_println {
+    () => ($crate::serial_print!("\n"));
+    ($fmt:expr) => ($crate::serial_print!(concat!($fmt, "\n")));
+    ($fmt:expr, $($arg:tt)*) => ($crate::serial_print!(
+        concat!($fmt, "\n"), $($arg)*));
+}

src/vga.rs

@@ -1,7 +1,7 @@
-use volatile::Volatile;
 use core::fmt;
 use lazy_static::lazy_static;
 use spin::Mutex;
+use volatile::Volatile;
 
 const BUFFER_HEIGHT: usize = 25;
 const BUFFER_WIDTH: usize = 80;
@@ -9,7 +9,7 @@ const BUFFER_WIDTH: usize = 80;
 lazy_static! {
     pub static ref WRITER: Mutex<Writer> = Mutex::new(Writer {
         column: 0,
-        color_code: ColorCode::new(Color::LightBlue, Color::Black),
+        color_code: ColorCode::new(Color::LightGreen, Color::Black),
         buffer: unsafe { &mut *(0xb8000 as *mut VgaBuffer) }
     });
 }
@@ -34,7 +34,6 @@ pub fn change_color(fg: Color, bg: Color) {
     WRITER.lock().change_color(ColorCode::new(fg, bg))
 }
 
-
 #[allow(dead_code)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(u8)]
@@ -90,7 +89,7 @@ impl Writer {
         for byte in s.bytes() {
             match byte {
                 0x20..=0x7e | b'\n' => self.write_byte(byte),
-                _ => self.write_byte(0xfe)
+                _ => self.write_byte(0xfe),
             }
         }
     }
@@ -109,7 +108,7 @@ impl Writer {
                 let color_code = self.color_code;
                 self.buffer.chars[row][col].write(VgaChar {
                     character: byte,
-                    color_code
+                    color_code,
                 });
                 self.column += 1;
             }
@@ -130,7 +129,7 @@ impl Writer {
     fn clear_row(&mut self, row: usize) {
         let blank = VgaChar {
             character: b' ',
-            color_code: self.color_code
+            color_code: self.color_code,
         };
         for col in 0..BUFFER_WIDTH {
             self.buffer.chars[row][col].write(blank);