initial commit

.cargo/config.toml

@@ -0,0 +1,9 @@
+[unstable]
+build-std-features = ["compiler-builtins-mem"]
+build-std = ["core", "compiler_builtins"]
+
+[build]
+target = "x86_64-rust_os.json"
+
+[target.'cfg(target_os = "none")']
+runner = "bootimage runner"

.gitignore

@@ -0,0 +1 @@
+/target

Cargo.lock

@@ -0,0 +1,81 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "bit_field"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed8765909f9009617974ab6b7d332625b320b33c326b1e9321382ef1999b5d56"
+
+[[package]]
+name = "bitflags"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+
+[[package]]
+name = "bootloader"
+version = "0.9.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a3c1ceed1cd9e61c7998100cc18c13d413aa40d018992b871ab8e7435ce6372"
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+dependencies = [
+ "spin",
+]
+
+[[package]]
+name = "rust_os"
+version = "0.1.0"
+dependencies = [
+ "bootloader",
+ "lazy_static",
+ "spin",
+ "uart_16550",
+ "volatile 0.2.7",
+ "x86_64",
+]
+
+[[package]]
+name = "spin"
+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 = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d95947de37ad0d2d9a4a4dd22e0d042e034e5cbd7ab53edbca0d8035e0a6a64d"
+dependencies = [
+ "bit_field",
+ "bitflags",
+ "volatile 0.4.4",
+]

Cargo.toml

@@ -0,0 +1,31 @@
+[package]
+name = "rust_os"
+version = "0.1.0"
+edition = "2018"
+
+[dependencies]
+bootloader = "0.9.8"
+volatile = "0.2.6"
+spin = "0.5.2"
+x86_64 = "0.14.2"
+uart_16550 = "0.2.0"
+
+[dependencies.lazy_static]
+version = "1.0"
+features = ["spin_no_std"]
+
+[package.metadata.bootimage]
+test-args = [
+    "-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "stdio",
+    "-display", "none"
+]
+test-success-exit-code = 33 
+test-timeout = 100
+
+[[test]]
+name = "should_panic"
+harness = false
+
+[[test]]
+name = "stack_overflow"
+harness = false

src/gdt.rs

@@ -0,0 +1,47 @@
+use x86_64::VirtAddr;
+use x86_64::structures::tss::TaskStateSegment;
+use x86_64::structures::gdt::{GlobalDescriptorTable, Descriptor};
+use x86_64::structures::gdt::SegmentSelector;
+use lazy_static::lazy_static;
+
+pub const DOUBLE_FAULT_IST_INDEX: u16 = 0;
+
+lazy_static! {
+    static ref TSS: TaskStateSegment = {
+        let mut tss = TaskStateSegment::new();
+        tss.interrupt_stack_table[DOUBLE_FAULT_IST_INDEX as usize] = {
+            const STACK_SIZE: usize = 4096 * 5;
+            static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE];
+
+            let stack_start = VirtAddr::from_ptr(unsafe { &STACK });
+            let stack_end = stack_start + STACK_SIZE;
+            stack_end
+        };
+        tss
+    };
+}
+
+lazy_static! {
+    static ref GDT: (GlobalDescriptorTable, Selectors) = {
+        let mut gdt = GlobalDescriptorTable::new();
+        let code_selector = gdt.add_entry(Descriptor::kernel_code_segment());
+        let tss_selector = gdt.add_entry(Descriptor::tss_segment(&TSS));
+        (gdt, Selectors { code_selector, tss_selector })
+    };
+}
+
+struct Selectors {
+    code_selector: SegmentSelector,
+    tss_selector: SegmentSelector,
+}
+
+pub fn init() {
+	use x86_64::instructions::segmentation::set_cs;
+	use x86_64::instructions::tables::load_tss;
+    
+	GDT.0.load();
+	unsafe {
+	    set_cs(GDT.1.code_selector);
+	    load_tss(GDT.1.tss_selector);
+	}
+}

src/interrupts.rs

@@ -0,0 +1,39 @@
+use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
+use crate::println;
+
+use lazy_static::lazy_static;
+use crate::gdt;
+
+lazy_static! {
+    static ref IDT: InterruptDescriptorTable = {
+        let mut idt = InterruptDescriptorTable::new();
+        idt.breakpoint.set_handler_fn(breakpoint_handler);
+        unsafe {
+            idt.double_fault.set_handler_fn(double_fault_handler)
+                .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX); // new
+        }
+
+        idt
+    };
+}
+    
+extern "x86-interrupt" fn double_fault_handler(
+	stack_frame: InterruptStackFrame, _error_code: u64) -> !
+{
+	panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
+}
+
+pub fn init_idt() {
+    IDT.load();
+}
+
+#[test_case]
+fn test_breakpoint_exception() {
+    x86_64::instructions::interrupts::int3();
+}
+
+extern "x86-interrupt" fn breakpoint_handler(
+    stack_frame: InterruptStackFrame)
+{
+    println!("EXCEPTION: BREAKPOINT\n{:#?}", stack_frame);
+}

src/lib.rs

@@ -0,0 +1,78 @@
+#![no_std]
+#![cfg_attr(test, no_main)]
+#![feature(custom_test_frameworks)]
+#![test_runner(crate::test_runner)]
+#![reexport_test_harness_main = "test_main"]
+#![feature(abi_x86_interrupt)]
+
+use core::panic::PanicInfo;
+
+pub mod serial;
+pub mod vga_buffer;
+pub mod interrupts;
+pub mod gdt;
+
+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]");
+    }
+}
+
+pub fn test_runner(tests: &[&dyn Testable]) {
+    serial_println!("Running {} tests", tests.len());
+    for test in tests {
+        test.run();
+    }
+    exit_qemu(QemuExitCode::Success);
+}
+
+pub fn test_panic_handler(info: &PanicInfo) -> ! {
+    serial_println!("[failed]\n");
+    serial_println!("Error: {}\n", info);
+    exit_qemu(QemuExitCode::Failed);
+    loop {}
+}
+
+pub fn init() {
+	gdt::init();
+	interrupts::init_idt();
+}
+
+#[cfg(test)]
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    init();      // new
+    test_main();
+    loop {}
+}
+
+#[cfg(test)]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    test_panic_handler(info)
+}
+
+#[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);
+    }
+}

src/main.rs

@@ -0,0 +1,36 @@
+#![no_std]
+#![no_main]
+#![feature(custom_test_frameworks)]
+#![test_runner(rust_os::test_runner)]
+#![reexport_test_harness_main = "test_main"]
+
+use core::panic::PanicInfo;
+use rust_os::println;
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    println!("Hello World{}", "!");
+
+    rust_os::init(); // new
+
+    // as before
+    #[cfg(test)]
+    test_main();
+
+    println!("It did not crash!");
+    loop {}
+}
+
+/// This function is called on panic.
+#[cfg(not(test))]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    println!("{}", info);
+    loop {}
+}
+
+#[cfg(test)]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    rust_os::test_panic_handler(info)
+}

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_buffer.rs

@@ -0,0 +1,168 @@
+use volatile::Volatile;
+
+const BUFFER_HEIGHT: usize = 25;
+const BUFFER_WIDTH: usize = 80;
+
+#[allow(dead_code)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum Color {
+    Black = 0,
+    Blue = 1,
+    Green = 2,
+    Cyan = 3,
+    Red = 4,
+    Magenta = 5,
+    Brown = 6,
+    LightGray = 7,
+    DarkGray = 8,
+    LightBlue = 9,
+    LightGreen = 10,
+    LightCyan = 11,
+    LightRed = 12,
+    Pink = 13,
+    Yellow = 14,
+    White = 15,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(transparent)]
+struct ColorCode(u8);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(C)]
+struct ScreenChar {
+    ascii_character: u8,
+    color_code: ColorCode,
+}
+
+#[repr(transparent)]
+struct Buffer {
+    chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
+}
+
+pub struct Writer {
+	column_position: usize,
+	color_code: ColorCode,
+	buffer: &'static mut Buffer,
+}
+
+impl ColorCode {
+	fn new(foreground: Color, background: Color) -> ColorCode {
+	    ColorCode((background as u8) << 4 | (foreground as u8))
+	}
+    }
+
+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;
+		    self.buffer.chars[row][col].write(ScreenChar {
+			ascii_character: byte,
+			color_code,
+		    });
+		    self.column_position += 1;
+		}
+	    }
+	}
+
+	pub fn write_string(&mut self, s: &str) {
+		for byte in s.bytes() {
+		    match byte {
+			// printable ASCII byte or newline
+			0x20..=0x7e | b'\n' => self.write_byte(byte),
+			// not part of printable ASCII range
+			_ => self.write_byte(0xfe),
+		    }
+	
+		}
+	}
+
+	fn new_line(&mut self) {
+		for row in 1..BUFFER_HEIGHT {
+		    for col in 0..BUFFER_WIDTH {
+			let character = self.buffer.chars[row][col].read();
+			self.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 {
+		    self.buffer.chars[row][col].write(blank);
+		}
+	}
+}
+
+use spin::Mutex;
+use lazy_static::lazy_static;
+lazy_static! {
+    pub static ref WRITER: Mutex<Writer> = Mutex::new(Writer {
+        column_position: 0,
+        color_code: ColorCode::new(Color::Yellow, Color::Black),
+        buffer: unsafe { &mut *(0xb8000 as *mut Buffer) },
+    });
+}
+
+use core::fmt;
+
+impl fmt::Write for Writer {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.write_string(s);
+        Ok(())
+    }
+}
+
+#[macro_export]
+macro_rules! print {
+    ($($arg:tt)*) => ($crate::vga_buffer::_print(format_args!($($arg)*)));
+}
+
+#[macro_export]
+macro_rules! println {
+    () => ($crate::print!("\n"));
+    ($($arg:tt)*) => ($crate::print!("{}\n", format_args!($($arg)*)));
+}
+
+#[doc(hidden)]
+pub fn _print(args: fmt::Arguments) {
+    use core::fmt::Write;
+    WRITER.lock().write_fmt(args).unwrap();
+}
+
+#[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().buffer.chars[BUFFER_HEIGHT - 2][i].read();
+        assert_eq!(char::from(screen_char.ascii_character), c);
+    }
+}

tests/basic_boot.rs

@@ -0,0 +1,26 @@
+#![no_std]
+#![no_main]
+#![feature(custom_test_frameworks)]
+#![reexport_test_harness_main = "test_main"]
+#![test_runner(rust_os::test_runner)]
+
+use core::panic::PanicInfo;
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    test_main();
+
+    loop {}
+}
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    rust_os::test_panic_handler(info)
+}
+
+use rust_os::println;
+
+#[test_case]
+fn test_println() {
+    println!("test_println output");
+}

tests/should_panic.rs

@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+use rust_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    should_fail();
+    serial_println!("[test did not panic]");
+    exit_qemu(QemuExitCode::Failed);
+    loop{}
+}
+
+fn should_fail() {
+    serial_print!("should_panic::should_fail...\t");
+    assert_eq!(0, 1);
+}
+
+#[panic_handler]
+fn panic(_info: &PanicInfo) -> ! {
+    serial_println!("[ok]");
+    exit_qemu(QemuExitCode::Success);
+    loop {}
+}

tests/stack_overflow.rs

@@ -0,0 +1,60 @@
+#![no_std]
+#![no_main]
+#![feature(abi_x86_interrupt)]
+
+use core::panic::PanicInfo;
+use rust_os::serial_print;
+use lazy_static::lazy_static;
+use x86_64::structures::idt::InterruptDescriptorTable;
+use rust_os::{exit_qemu, QemuExitCode, serial_println};
+use x86_64::structures::idt::InterruptStackFrame;
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    serial_print!("stack_overflow::stack_overflow...\t");
+
+    rust_os::gdt::init();
+    init_test_idt();
+
+    // trigger a stack overflow
+    stack_overflow();
+
+    panic!("Execution continued after stack overflow");
+}
+
+#[allow(unconditional_recursion)]
+fn stack_overflow() {
+    stack_overflow(); // for each recursion, the return address is pushed
+    volatile::Volatile::new(0).read(); // prevent tail recursion optimizations
+}
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    rust_os::test_panic_handler(info)
+}
+
+lazy_static! {
+    static ref TEST_IDT: InterruptDescriptorTable = {
+        let mut idt = InterruptDescriptorTable::new();
+        unsafe {
+            idt.double_fault
+                .set_handler_fn(test_double_fault_handler)
+                .set_stack_index(rust_os::gdt::DOUBLE_FAULT_IST_INDEX);
+        }
+
+        idt
+    };
+}
+
+pub fn init_test_idt() {
+    TEST_IDT.load();
+}
+
+extern "x86-interrupt" fn test_double_fault_handler(
+    _stack_frame: InterruptStackFrame,
+    _error_code: u64,
+) -> ! {
+    serial_println!("[ok]");
+    exit_qemu(QemuExitCode::Success);
+    loop {}
+}

x86_64-rust_os.json

@@ -0,0 +1,15 @@
+{
+	"llvm-target": "x86_64-unknown-none",
+	"data-layout": "e-m:e-i64:64-f80:128-n8:16:32:64-S128",
+	"arch": "x86_64",
+	"target-endian": "little",
+	"target-pointer-width": "64",
+	"target-c-int-width": "32",
+	"os": "none",
+	"executables": true,
+	"linker-flavor": "ld.lld",
+	"linker": "rust-lld",
+	"panic-strategy": "abort",
+	"disable-redzone": true,
+	"features": "-mmx,-sse,+soft-float"
+}