Merge pull request #1436 from phil-opp/post-02-fix-target

Fix: `target-pointer-width` field now expects an integer

Cargo.lock

@@ -1,40 +1,16 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "blog_os"
 version = "0.1.0"
 dependencies = [
  "bootloader",
- "lazy_static",
- "spin",
- "volatile",
 ]
 
 [[package]]
 name = "bootloader"
-version = "0.9.29"
+version = "0.9.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "365861702868e2a37b4247aaecc7bd8f4389baec8d025497ad8ba7ff37ee9440"
+checksum = "7bdfddac270bbdd45903296bc1caf29a7fdce6b326aaf0bbab7f04c5f98b7447"
-
-[[package]]
-name = "lazy_static"
-version = "1.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
-dependencies = [
- "spin",
-]
-
-[[package]]
-name = "spin"
-version = "0.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
-
-[[package]]
-name = "volatile"
-version = "0.2.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f6b06ad3ed06fef1713569d547cdbdb439eafed76341820fb0e0344f29a41945"

Cargo.toml

@@ -2,13 +2,12 @@
 name = "blog_os"
 version = "0.1.0"
 authors = ["Philipp Oppermann <dev@phil-opp.com>"]
-edition = "2018"
+edition = "2024"
 
 [dependencies]
 bootloader = "0.9"
-volatile = "0.2.6"
-spin = "0.5.2"
 
-[dependencies.lazy_static]
+[[bin]]
-version = "1.0"
+name = "blog_os"
-features = ["spin_no_std"]
+test = false
+bench = false

README.md

@@ -1,10 +1,10 @@
-# Blog OS (VGA Text Mode)
+# Blog OS (A Minimal Rust Kernel)
 
-[![Build Status](https://github.com/phil-opp/blog_os/workflows/Code/badge.svg?branch=post-03)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Code%22+branch%3Apost-03)
+[![Build Status](https://github.com/phil-opp/blog_os/workflows/Code/badge.svg?branch=post-02)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Code%22+branch%3Apost-02)
 
-This repository contains the source code for the [VGA Text Mode][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
+This repository contains the source code for the [A Minimal Rust Kernel][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
 
-[post]: https://os.phil-opp.com/vga-text-mode/
+[post]: https://os.phil-opp.com/minimal-rust-kernel/
 
 **Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
 

src/main.rs

@@ -3,18 +3,24 @@
 
 use core::panic::PanicInfo;
 
-mod vga_buffer;
+static HELLO: &[u8] = b"Hello World!";
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
-    println!("Hello World{}", "!");
+    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;
+        }
+    }
 
     loop {}
 }
 
 /// This function is called on panic.
 #[panic_handler]
-fn panic(info: &PanicInfo) -> ! {
+fn panic(_info: &PanicInfo) -> ! {
-    println!("{}", info);
     loop {}
 }

src/vga_buffer.rs

@@ -1,171 +0,0 @@
-use core::fmt;
-use lazy_static::lazy_static;
-use spin::Mutex;
-use volatile::Volatile;
-
-lazy_static! {
-    /// A global `Writer` instance that can be used for printing to the VGA text buffer.
-    ///
-    /// Used by the `print!` and `println!` macros.
-    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) },
-    });
-}
-
-/// The standard color palette in VGA text mode.
-#[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,
-}
-
-/// A combination of a foreground and a background color.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(transparent)]
-struct ColorCode(u8);
-
-impl ColorCode {
-    /// Create a new `ColorCode` with the given foreground and background colors.
-    fn new(foreground: Color, background: Color) -> ColorCode {
-        ColorCode((background as u8) << 4 | (foreground as u8))
-    }
-}
-
-/// A screen character in the VGA text buffer, consisting of an ASCII character and a `ColorCode`.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(C)]
-struct ScreenChar {
-    ascii_character: u8,
-    color_code: ColorCode,
-}
-
-/// The height of the text buffer (normally 25 lines).
-const BUFFER_HEIGHT: usize = 25;
-/// The width of the text buffer (normally 80 columns).
-const BUFFER_WIDTH: usize = 80;
-
-/// A structure representing the VGA text buffer.
-#[repr(transparent)]
-struct Buffer {
-    chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
-}
-
-/// A writer type that allows writing ASCII bytes and strings to an underlying `Buffer`.
-///
-/// Wraps lines at `BUFFER_WIDTH`. Supports newline characters and implements the
-/// `core::fmt::Write` trait.
-pub struct Writer {
-    column_position: usize,
-    color_code: ColorCode,
-    buffer: &'static mut Buffer,
-}
-
-impl Writer {
-    /// Writes an ASCII byte to the buffer.
-    ///
-    /// Wraps lines at `BUFFER_WIDTH`. Supports the `\n` newline character.
-    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;
-            }
-        }
-    }
-
-    /// Writes the given ASCII string to the buffer.
-    ///
-    /// Wraps lines at `BUFFER_WIDTH`. Supports the `\n` newline character. Does **not**
-    /// support strings with non-ASCII characters, since they can't be printed in the VGA text
-    /// mode.
-    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),
-            }
-        }
-    }
-
-    /// Shifts all lines one line up and clears the last row.
-    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;
-    }
-
-    /// Clears a row by overwriting it with blank characters.
-    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(())
-    }
-}
-
-/// Like the `print!` macro in the standard library, but prints to the VGA text buffer.
-#[macro_export]
-macro_rules! print {
-    ($($arg:tt)*) => ($crate::vga_buffer::_print(format_args!($($arg)*)));
-}
-
-/// Like the `println!` macro in the standard library, but prints to the VGA text buffer.
-#[macro_export]
-macro_rules! println {
-    () => ($crate::print!("\n"));
-    ($($arg:tt)*) => ($crate::print!("{}\n", format_args!($($arg)*)));
-}
-
-/// Prints the given formatted string to the VGA text buffer through the global `WRITER` instance.
-#[doc(hidden)]
-pub fn _print(args: fmt::Arguments) {
-    use core::fmt::Write;
-    WRITER.lock().write_fmt(args).unwrap();
-}

x86_64-blog_os.json

@@ -3,8 +3,8 @@
     "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-pointer-width": 64,
-    "target-c-int-width": "32",
+    "target-c-int-width": 32,
     "os": "none",
     "executables": true,
     "linker-flavor": "ld.lld",