From 8e83ca2f19e03d92e5c541d51a1ca5bd82b87d03 Mon Sep 17 00:00:00 2001 From: Timothy Warren Date: Tue, 24 Sep 2019 10:20:27 -0400 Subject: [PATCH] post-03 --- Cargo.lock | 24 ++++++++ Cargo.toml | 6 ++ src/main.rs | 16 ++---- src/vga_buffer.rs | 144 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 179 insertions(+), 11 deletions(-) create mode 100644 src/vga_buffer.rs diff --git a/Cargo.lock b/Cargo.lock index 9599aca..12c54ff 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -5,6 +5,9 @@ name = "blog_os" version = "0.1.0" dependencies = [ "bootloader 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)", + "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)", + "spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)", + "volatile 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)", ] [[package]] @@ -12,5 +15,26 @@ name = "bootloader" version = "0.8.1" source = "registry+https://github.com/rust-lang/crates.io-index" +[[package]] +name = "lazy_static" +version = "1.4.0" +source = "registry+https://github.com/rust-lang/crates.io-index" +dependencies = [ + "spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)", +] + +[[package]] +name = "spin" +version = "0.5.2" +source = "registry+https://github.com/rust-lang/crates.io-index" + +[[package]] +name = "volatile" +version = "0.2.6" +source = "registry+https://github.com/rust-lang/crates.io-index" + [metadata] "checksum bootloader 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "45dd858bd74a742ec0fe887722952c263abd0825aa8d33a3704917a97d7bd41e" +"checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646" +"checksum spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d" +"checksum volatile 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "6af0edf5b4faacc31fc51159244d78d65ec580f021afcef7bd53c04aeabc7f29" diff --git a/Cargo.toml b/Cargo.toml index cc56755..82b7a36 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -8,6 +8,12 @@ edition = "2018" [dependencies] bootloader = "0.8.1" +spin = "0.5.2" +volatile = "0.2.6" + +[dependencies.lazy_static] +version = "1.4.0" +features = ["spin_no_std"] [profile.dev] panic = "abort" diff --git a/src/main.rs b/src/main.rs index 8c705df..f4f8714 100644 --- a/src/main.rs +++ b/src/main.rs @@ -3,24 +3,18 @@ use core::panic::PanicInfo; +mod vga_buffer; + /// This function is called on panic. #[panic_handler] -fn panic(_info: &PanicInfo) -> ! { +fn panic(info: &PanicInfo) -> ! { + println!("{}", info); loop {} } -static HELLO: &[u8] = b"Hello World!"; - #[no_mangle] pub extern "C" fn _start() -> ! { - let vga_buffer = 0xb8000 as *mut u8; - - for (i, &byte) in HELLO.iter().enumerate() { - unsafe { - *vga_buffer.offset(i as isize * 2) = byte; - *vga_buffer.offset(i as isize * 2 + 1) = 0xb; - } - } + panic!("Some panic message"); loop {} } diff --git a/src/vga_buffer.rs b/src/vga_buffer.rs new file mode 100644 index 0000000..7252107 --- /dev/null +++ b/src/vga_buffer.rs @@ -0,0 +1,144 @@ +use core::fmt; +use lazy_static::lazy_static; +use spin::Mutex; +use volatile::Volatile; + +#[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); + +impl ColorCode { + fn new(foreground: Color, background: Color) -> ColorCode { + ColorCode((background as u8) << 4 | (foreground as u8)) + } +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +#[repr(C)] +struct ScreenChar { + ascii_character: u8, + color_code: ColorCode, +} + +const BUFFER_HEIGHT: usize = 25; +const BUFFER_WIDTH: usize = 80; + +#[repr(transparent)] +struct Buffer { + chars: [[Volatile; BUFFER_WIDTH]; BUFFER_HEIGHT], +} + +pub struct Writer { + column_position: usize, + color_code: ColorCode, + buffer: &'static mut Buffer, +} + +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); + } + } +} + +impl fmt::Write for Writer { + fn write_str(&mut self, s: &str) -> fmt::Result { + self.write_string(s); + Ok(()) + } +} + +lazy_static!{ + pub static ref WRITER: Mutex = Mutex::new(Writer { + column_position: 0, + color_code: ColorCode::new(Color::Yellow, Color::Black), + buffer: unsafe { &mut *(0xb8000 as *mut Buffer) }, + }); +} + +#[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(); +} \ No newline at end of file