5 files changed, 104 insertions, 4 deletions

diff --git a/src/.sync.rs.swp b/src/.sync.rs.swp
deleted file mode 100644
index 462e2ef..0000000
--- a/src/.sync.rs.swp
+++ /dev/null
diff --git a/src/kernel.rs b/src/kernel.rs
index 2382345..cf594cd 100644
--- a/src/kernel.rs
+++ b/src/kernel.rs
@@ -5,13 +5,44 @@
 #![no_std] // don't link the Rust standard library
 #![no_main] // disable all Rust-level entry points
 #![feature(const_mut_refs)]
+#![feature(custom_test_frameworks)]
+#![test_runner(crate::test_runner)]
+#![reexport_test_harness_main = "test_main"]
 
 mod sync;
 mod vga;
+mod serial;
 use vga::*;
+use serial::*;
 use core::panic::PanicInfo;
 
+pub trait Testable {
+	fn run(&self) -> ();
+}
+
+impl<T> Testable for T
+where
+	T: Fn(),
+{
+	fn run(&self) {
+		serial_print!("{}...\t", core::any::type_name::<T>());
+		self();
+		serial_println!("[ok]");
+	}
+}
+
+/// This function is called on panic.
+#[cfg(test)]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+	serial_println!("[failed]\n");
+	serial_println!("Error: {}\n", info);
+	exit_qemu(QemuExitCode::Failed);
+	loop {}
+}
+
 /// This function is called on panic.
+#[cfg(not(test))]
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
 	println!("{}", info);
@@ -20,15 +51,52 @@ fn panic(info: &PanicInfo) -> ! {
 
 fn kernel_init() {
 	WRITER.init();
+	SERIAL1.init();
 }
 
 #[no_mangle]
 pub extern "C" fn _start() -> ! {
 	kernel_init();
 
-	WRITER.write_string("Hello World!");
-	WRITER.write_string("\n\nHi\n");
-	println!("{}", 5);
+	#[cfg(not(test))]
+	{
+		WRITER.write_string("Hello World!");
+		WRITER.write_string("\n\nHi\n");
+		println!("{}", 5);
+	}
+
+	#[cfg(test)]
+	test_main();
 
 	loop {}
 }
+
+#[cfg(test)]
+fn test_runner(tests: &[&dyn Testable]) {
+	serial_println!("Running {} tests", tests.len());
+	for test in tests {
+		test.run();
+	}
+	exit_qemu(QemuExitCode::Success);
+}
+
+#[test_case]
+fn trivial_assertion() {
+	assert_eq!(1, 1);
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u32)]
+pub enum QemuExitCode {
+	Success = 0x10,
+	Failed = 0x11,
+}
+
+pub fn exit_qemu(exit_code: QemuExitCode) {
+	use x86_64::instructions::port::Port;
+
+	unsafe {
+		let mut port = Port::new(0xf4);
+		port.write(exit_code as u32);
+	}
+}
diff --git a/src/vga/.buffer.rs.swp b/src/vga/.buffer.rs.swp
index 0ce0feb..012b7b1 100644
--- a/src/vga/.buffer.rs.swp
+++ b/src/vga/.buffer.rs.swp
diff --git a/src/vga/.mod.rs.swp b/src/vga/.mod.rs.swp
deleted file mode 100644
index 6071785..0000000
--- a/src/vga/.mod.rs.swp
+++ /dev/null
diff --git a/src/vga/buffer.rs b/src/vga/buffer.rs
index 34c665d..4ca001c 100644
--- a/src/vga/buffer.rs
+++ b/src/vga/buffer.rs
@@ -109,6 +109,7 @@ impl NullLock<VgaWriter> {
 		});
 	}
 
+	#[allow(dead_code)]
 	pub fn write_string(&self, s: &str) {
 		self.lock(|writer| {
 			writer.write_string(s);
@@ -152,6 +153,37 @@ macro_rules! println {
 
 pub static WRITER: NullLock<VgaWriter> = NullLock::new(VgaWriter {
 	column_position: 0,
-	color_code: ColorCode::new(Color::Yellow, Color::Black),
+	color_code: ColorCode::new(Color::LightBlue, Color::Black),
 	buffer: None,
 });
+
+#[test_case]
+fn test_println_simple() {
+	println!("test_println_simple output");
+}
+
+#[test_case]
+fn test_println_many() {
+	for _ in 0..200 {
+		println!("test_println_many output");
+	}
+}
+
+#[test_case]
+fn test_println_output() {
+	let s = "Some test string that fits on a single line";
+	println!("{}", s);
+	for (i, c) in s.chars().enumerate() {
+		let screen_char = WRITER.lock(|writer| {
+			if let Some(buffer) = &writer.buffer {
+				return buffer.chars[BUFFER_HEIGHT - 2][i].read();
+			} else {
+				return ScreenChar {
+					ascii_character: b' ',
+					color_code: ColorCode::new(Color::LightBlue, Color::Black),
+				};
+			}
+		});
+		assert_eq!(char::from(screen_char.ascii_character), c);
+	}
+}