Merge pull request #1412 from tigeryant/post-01

Added [[bin]] section to Cargo.toml

.cargo/config.toml

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

.github/workflows/code.yml

@@ -56,16 +56,21 @@ jobs:
         with:
           profile: minimal
           toolchain: nightly
-      - name: Install bootimage
-        run: cargo install bootimage --debug
       - name: Checkout Repository
         uses: actions/checkout@v2
-      - name: Install Rustup Components
-        run: rustup component add rust-src llvm-tools-preview
-      - name: Run `cargo bootimage`
-        uses: actions-rs/cargo@v1
-        with:
-          command: bootimage
+      - name: Add thumbv7em-none-eabihf Target
+        run: rustup target add thumbv7em-none-eabihf
+      - name: Build for thumbv7em-none-eabihf
+        run: cargo build --target thumbv7em-none-eabihf
+      - name: Build for Linux
+        if: runner.os == 'Linux'
+        run: cargo rustc -- -C link-arg=-nostartfiles
+      - name: Build for macOS
+        if: runner.os == 'macOS'
+        run: cargo rustc -- -C link-args="-e __start -static -nostartfiles"
+      - name: Build for Windows
+        if: runner.os == 'Windows'
+        run: cargo rustc -- -C link-args="/ENTRY:_start /SUBSYSTEM:console"
 
   check_formatting:
     name: Check Formatting

Cargo.lock

@@ -5,36 +5,3 @@ version = 3
 [[package]]
 name = "blog_os"
 version = "0.1.0"
-dependencies = [
- "bootloader",
- "lazy_static",
- "spin",
- "volatile",
-]
-
-[[package]]
-name = "bootloader"
-version = "0.9.23"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6e02311b16c9819e7c72866d379cdd3026c3b7b25c1edf161f548f8e887e7ff"
-
-[[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 +2,17 @@
 name = "blog_os"
 version = "0.1.0"
 authors = ["Philipp Oppermann <dev@phil-opp.com>"]
-edition = "2018"
+edition = "2024"
 
 [dependencies]
-bootloader = "0.9.8"
-volatile = "0.2.6"
-spin = "0.5.2"
 
-[dependencies.lazy_static]
-version = "1.0"
-features = ["spin_no_std"]
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"
+
+[[bin]]
+name = "blog_os"
+test = false
+bench = false

README.md

@@ -1,61 +1,25 @@
-# Blog OS (VGA Text Mode)
+# Blog OS (A Freestanding Rust Binary)
 
-[![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-01)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Code%22+branch%3Apost-01)
 
-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 Freestanding Rust Binary][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/freestanding-rust-binary/
 
 **Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
 
 ## Building
 
-This project requires a nightly version of Rust because it uses some unstable features. At least nightly _2020-07-15_ is required for building. You might need to run `rustup update nightly --force` to update to the latest nightly even if some components such as `rustfmt` are missing it.
-
-You can build the project by running:
+To build the project on Linux, run:
 
 ```
-cargo build
+cargo rustc -- -Clink-arg=-nostartfiles
 ```
 
-To create a bootable disk image from the compiled kernel, you need to install the [`bootimage`] tool:
-
-[`bootimage`]: https://github.com/rust-osdev/bootimage
-
-```
-cargo install bootimage
-```
-
-After installing, you can create the bootable disk image by running:
-
-```
-cargo bootimage
-```
-
-This creates a bootable disk image in the `target/x86_64-blog_os/debug` directory.
+The entry point and the build command differ slightly on macOS and Windows. See the [post] for more information.
 
 Please file an issue if you have any problems.
 
-## Running
-
-You can run the disk image in [QEMU] through:
-
-[QEMU]: https://www.qemu.org/
-
-```
-cargo run
-```
-
-[QEMU] and the [`bootimage`] tool need to be installed for this.
-
-You can also write the image to an USB stick for booting it on a real machine. On Linux, the command for this is:
-
-```
-dd if=target/x86_64-blog_os/debug/bootimage-blog_os.bin of=/dev/sdX && sync
-```
-
-Where `sdX` is the device name of your USB stick. **Be careful** to choose the correct device name, because everything on that device is overwritten.
-
 ## License
 
 Licensed under either of

rust-toolchain

@@ -1 +0,0 @@
-nightly

src/main.rs

@@ -3,18 +3,13 @@
 
 use core::panic::PanicInfo;
 
-mod vga_buffer;
-
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
-    println!("Hello World{}", "!");
-
     loop {}
 }
 
 /// This function is called on panic.
 #[panic_handler]
-fn panic(info: &PanicInfo) -> ! {
-    println!("{}", info);
+fn panic(_info: &PanicInfo) -> ! {
     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

@@ -1,15 +0,0 @@
-{
-    "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"
-  }