.gitignore

@@ -1,5 +1,4 @@
-target
+/kernel/target
-/kernel/Cargo.lock
 /build
 /binutils
 /gcc

kernel/Cargo.lock

@@ -3,5 +3,5 @@
 version = 3
 
 [[package]]
-name = "std"
+name = "kernel"
 version = "0.1.0"

kernel/Cargo.toml

@@ -3,8 +3,4 @@ name = "kernel"
 version = "0.1.0"
 edition = "2021"
 
-[workspace]
-members = ["std"]
-
 [dependencies]
-std = { path = "std" }

kernel/src/main.rs

@@ -1,13 +1,19 @@
 #![no_std]
 #![no_main]
 
-use std::println;
-
 #[no_mangle]
 pub extern "C" fn kernel_main() -> ! {
-    let a = 4;
+    let vga_buffer = 0xb8000 as *mut u8;
-    println!("Hiii :3");
+
-    println!("{}", a);
+    let string: &[u8] = b":3";
+    for (i, &byte) in string.iter().enumerate() {
+        unsafe {
+            *vga_buffer.offset(i as isize * 2) = byte;
+            *vga_buffer.offset(i as isize * 2 + 1) = 0xf;
+        }
+    }
+
+
     loop {}
 }
  

kernel/std/Cargo.toml

@@ -1,8 +0,0 @@
-[package]
-name = "std"
-version = "0.1.0"
-edition = "2021"
-
-[dependencies]
-lazy_static = { version = "1.4.0", features = ["spin_no_std"] }
-spin = "0.9.8"

kernel/std/src/lib.rs

@@ -1,3 +0,0 @@
-#![no_std]
-
-pub mod vga_buffer;

kernel/std/src/vga_buffer.rs

@@ -1,132 +0,0 @@
-use core::fmt::{self, Write};
-
-use lazy_static::lazy_static;
-use spin::Mutex;
-
-#[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)]
-pub struct ColorCode(u8);
-
-impl ColorCode {
-    pub 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: [[ScreenChar; BUFFER_WIDTH]; BUFFER_HEIGHT],
-}
-
-pub struct Writer {
-    col: usize,
-    row: usize,
-    buffer: &'static mut Buffer,
-}
-
-impl Writer {
-    pub fn write_byte(&mut self, byte: u8) {
-        self.write_byte_color(byte, ColorCode::new(Color::White, Color::Black));
-    }
-
-    pub fn write_byte_color(&mut self, byte: u8, color: ColorCode) {
-        match byte {
-            b'\n' => self.new_line(),
-            byte => {
-                if self.col >= BUFFER_WIDTH {
-                    self.new_line();
-                }
-
-                let row = self.row;
-                let col = self.col;
-
-                let color_code = color;
-                self.buffer.chars[row][col] = ScreenChar {
-                    ascii_character: byte,
-                    color_code,
-                };
-                self.col += 1;
-            }
-        }
-    }
-
-    pub fn write_string(&mut self, s: &str) {
-        self.write_string_color(s, ColorCode::new(Color::White, Color::Black));
-    }
-
-    pub fn write_string_color(&mut self, s: &str, color: ColorCode) {
-        for char in s.bytes() {
-            match char {
-                0x20..=0x7e | b'\n' => self.write_byte_color(char, color),
-                _ => self.write_byte(0xfe),
-            }
-        }
-    }
-
-    fn new_line(&mut self) {
-        self.row += 1;
-        self.col = 0;
-    }
-}
-
-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<Writer> = Mutex::new(Writer {
-        col: 0,
-        row: 0,
-        buffer: unsafe { &mut *(0xB8000 as *mut Buffer) },
-    });
-}
-
-#[doc(hidden)]
-pub fn _print(args: fmt::Arguments) {
-    WRITER.lock().write_fmt(args).unwrap()
-}
-
-#[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)*)));
-}

log/2024-03-26.md

@@ -350,15 +350,6 @@ fn panic(_info: &core::panic::PanicInfo) -> ! {
 # Building the kernel
 To build the kernel I just run `cargo build` in the `kernel` directory. This will produce a binary called `kernel/target/i686-bare-metal/debug/kernel.elf`. I now have a multiboot enabled kernel :)
 
-# Grub
-Now to turn the kernel into a ISO file with a bootloader, I used grub. To configure grub I needed to create a directory for it. I made `build/isodir/boot/grub/grub.cfg` containing this:
-```
-menuentry "geos" {
-	multiboot /boot/geos.bin
-}
-```
-Then I copied `kernel/target/i686-bare-metal/debug/kernel.elf` to `isodir/boot/geos.bin`. Then I ran `grub-mkrescue -o build/geos.iso build/isodir` to make an ISO containing my OS and grub. Yippee
-
 # File structure
 ```
 geos/

log/2024-03-27.md

@@ -1,189 +0,0 @@
-# VGA text
-Hello. Today I succesfully made a `println!` macro.
-
-## std
-To following conventions I decided to make a `std` library. To do this I made a workspace in `kernel/`.
-
-`kernel/Cargo.toml`
-```toml
-[package]
-name = "kernel"
-version = "0.1.0"
-edition = "2021"
-
-[workspace]
-members = ["std"]
-
-[dependencies]
-std = { path = "std" }
-```
-
-## lib.rs
-To not have one big spaghetti file I separated out all the individal modules into different files.
-`kernel/std/src/lib.rs`
-```rust
-#![no_std]
-
-pub mod vga_buffer;
-```
-
-## vga_buffer.rs
-First step for a VGA text driver is to be able to represent data.
-
-`kernel/std/src/lib.rs`
-```rust
-#[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)] // Store this as a u8
-pub struct ColorCode(u8);
-
-impl ColorCode {
-    pub fn new(foreground: Color, background: Color) -> ColorCode {
-        ColorCode((background as u8) << 4 | (foreground as u8))
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(C)] // Tells rust to store this like a struct in C, i.e. store this as 2 bytes
-struct ScreenChar {
-    ascii_character: u8,
-    color_code: ColorCode,
-}
-
-const BUFFER_HEIGHT: usize = 25;
-const BUFFER_WIDTH: usize = 80;
-
-#[repr(transparent)]
-struct Buffer {
-    chars: [[ScreenChar; BUFFER_WIDTH]; BUFFER_HEIGHT],
-}
-```
-
-Now I can represent the VGA text buffer. To write to this I want to make a writer struct that implements `fmt::Write`.
-```rust
-pub struct Writer {
-    col: usize,
-    row: usize,
-    buffer: &'static mut Buffer,
-}
-
-impl Writer {
-    pub fn write_byte(&mut self, byte: u8) {
-        self.write_byte_color(byte, ColorCode::new(Color::White, Color::Black));
-    }
-
-    pub fn write_byte_color(&mut self, byte: u8, color: ColorCode) {
-        match byte {
-            b'\n' => self.new_line(),
-            byte => {
-                if self.col >= BUFFER_WIDTH {
-                    self.new_line();
-                }
-
-                let row = self.row;
-                let col = self.col;
-
-                let color_code = color;
-                self.buffer.chars[row][col] = ScreenChar {
-                    ascii_character: byte,
-                    color_code,
-                };
-                self.col += 1;
-            }
-        }
-    }
-
-    pub fn write_string(&mut self, s: &str) {
-        self.write_string_color(s, ColorCode::new(Color::White, Color::Black));
-    }
-
-    pub fn write_string_color(&mut self, s: &str, color: ColorCode) {
-        for char in s.bytes() {
-            match char {
-                0x20..=0x7e | b'\n' => self.write_byte_color(char, color), // Ascii Character
-                _ => self.write_byte(0xfe), // Non ascii
-            }
-        }
-    }
-
-    fn new_line(&mut self) {
-        self.row += 1;
-        self.col = 0;
-    }
-}
-
-impl fmt::Write for Writer {
-    fn write_str(&mut self, s: &str) -> fmt::Result {
-        self.write_string(s);
-        Ok(())
-    }
-}
-```
-
-The problem now becomes that I can create a `Writer` but I don't have a global position, so it will just overwrite what I wrote last time. To solve this I can use a static variable. But a static variable won't be mutable. This can be solved with `Mutex` in the spin crate and `lazy_static`.
-
-`kernel/std/Cargo.toml`
-```toml
-[package]
-name = "std"
-version = "0.1.0"
-edition = "2021"
-
-[dependencies]
-lazy_static = { version = "1.4.0", features = ["spin_no_std"] }
-spin = "0.9.8"
-```
-
-and to make a static variable I wrote (copied from [here](https://os.phil-opp.com/vga-text-mode/)) this
-```rust
-lazy_static! {
-    pub static ref WRITER: Mutex<Writer> = Mutex::new(Writer {
-        col: 0,
-        row: 0,
-        buffer: unsafe { &mut *(0xB8000 as *mut Buffer) },
-    });
-}
-```
-in `kernel/std/src/vga_buffer.rs`.
-
-Last step is just to add a function and 2 macros
-```rust
-#[doc(hidden)]
-pub fn _print(args: fmt::Arguments) {
-    WRITER.lock().write_fmt(args).unwrap()
-}
-
-#[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)*)));
-}
-```
-
-Huge thanks to @phil-opp for [os.phil-opp.com](https://os.phil-opp.com/)
-