updated README

.cargo/config.toml

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

Cargo.toml

@@ -15,3 +15,10 @@ panic = "abort" # disable stack unwinding on panic
 panic = "abort" # disable stack unwinding on panic
 
 [dependencies]
+bootloader = "0.9"
+volatile = "0.2.6"
+spin = "0.5.2"
+
+[dependencies.lazy_static]
+version = "1.0"
+features = ["spin_no_std"]

README.md

@@ -1 +1,16 @@
+### ABOUT
+
 trying to make a toy OS in rust following [this](https://os.phil-opp.com)
+
+### DEPENDENCIES
+
+- qemu
+- [cargo bootimage](https://github.com/rust-osdev/bootimage)
+
+### HOWTO
+
+to run this just install the [dependencies](#dependencies) and do:
+
+```shell
+cargo run
+```

src/main.rs

@@ -3,11 +3,19 @@
 
 use core::panic::PanicInfo;
 
+mod vga_buffer;
+
+static HELLO: &[u8] = b"Hello toto :3";
+
 // this function is the entry point since the linker
 // looks for a function named `_start` by default
 #[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
-    loop{}
+    use core::fmt::Write;
+    vga_buffer::WRITER.lock().write_str("TOTOTO !!!! :3").unwrap();
+    write!(vga_buffer::WRITER.lock(), ", smoking cigarette in the shower when they get wet i just light another :{}", 3).unwrap();
+
+    loop {}
 }
 
 // called on panic

src/vga_buffer.rs

@@ -0,0 +1,138 @@
+use core::fmt;
+use volatile::Volatile;
+use lazy_static::lazy_static;
+use spin::Mutex;
+
+lazy_static! {
+    pub static ref WRITER: Mutex<Writer> = Mutex::new(Writer {
+        column_position: 0,
+        color_code: ColorCode::new(Color::Pink, Color::Black),
+        buffer: unsafe { &mut *(0xB8000 as *mut Buffer) },
+    });
+}
+
+#[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_carachter: u8,
+    color_code: ColorCode,
+}
+
+const BUFFER_HEIGHT: usize = 25;
+const BUFFER_WIDTH: usize = 80;
+
+#[repr(transparent)]
+struct Buffer {
+    // wrapping the `ScreenChar` in a generic `Volatile`
+    // type prevents the compiler from optimizing writes
+    // away since the program only writes to it but never
+    // reads from it.
+    // by making it volatile we signal to the compiler
+    // that our write call have side-effects
+    // to interact with this type the `write()` and `read()`
+    // methods must be used now
+    chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
+}
+
+pub struct Writer {
+    column_position: usize,
+    color_code: ColorCode,
+    buffer: &'static mut Buffer,
+}
+
+impl fmt::Write for Writer {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.write_string(s);
+        Ok(())
+    }
+}
+
+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_carachter: 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;
+    }
+
+    // this method clears a row by overwriting all of its
+    // characters with a space character.
+    fn clear_row(&mut self, row: usize) {
+        let blank = ScreenChar {
+            ascii_carachter: b' ',
+            color_code: self.color_code,
+        };
+
+        for col in 0..BUFFER_WIDTH {
+            self.buffer.chars[row][col].write(blank);
+        }
+    }
+}

x86_64-totos.json

@@ -0,0 +1,16 @@
+{
+    "llvm-target": "x86_64-unknown-none",
+    "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-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",
+    "rustc-abi": "x86-softfloat"
+}