Merge branch 'post-02' into post-03

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

.github/workflows/code.yml

@@ -67,31 +67,6 @@ jobs:
         with:
           command: bootimage
 
-      # install QEMU
-      - name: Install QEMU (Linux)
-        run: sudo apt update && sudo apt install qemu-system-x86
-        if: runner.os == 'Linux'
-      - name: Install QEMU (macOS)
-        run: brew install qemu
-        if: runner.os == 'macOS'
-        env:
-          HOMEBREW_NO_AUTO_UPDATE: 1
-          HOMEBREW_NO_BOTTLE_SOURCE_FALLBACK: 1
-          HOMEBREW_NO_INSTALL_CLEANUP: 1
-      - name: Install QEMU (Windows)
-        run: |
-          choco install qemu --version 2021.5.5
-          echo "$Env:Programfiles\qemu" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-        if: runner.os == 'Windows'
-        shell: pwsh
-      - name: "Print QEMU Version"
-        run: qemu-system-x86_64 --version
-
-      - name: Run `cargo test`
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-
   check_formatting:
     name: Check Formatting
     runs-on: ubuntu-latest

Cargo.lock

@@ -1,18 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
-
-[[package]]
-name = "bit_field"
-version = "0.10.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dcb6dd1c2376d2e096796e234a70e17e94cc2d5d54ff8ce42b28cef1d0d359a4"
-
-[[package]]
-name = "bitflags"
-version = "1.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+version = 4
 
 [[package]]
 name = "blog_os"
@@ -20,25 +8,23 @@ version = "0.1.0"
 dependencies = [
  "bootloader",
  "lazy_static",
- "spin",
- "uart_16550",
- "volatile 0.2.7",
- "x86_64",
+ "spin 0.5.2",
+ "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"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 dependencies = [
- "spin",
+ "spin 0.9.8",
 ]
 
 [[package]]
@@ -48,34 +34,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
 
 [[package]]
-name = "uart_16550"
-version = "0.2.14"
+name = "spin"
+version = "0.9.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "503a6c0e6d82daa87985e662d120c0176b09587c92a68db22781b28ae95405dd"
-dependencies = [
- "bitflags",
- "x86_64",
-]
+checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
 
 [[package]]
 name = "volatile"
 version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6b06ad3ed06fef1713569d547cdbdb439eafed76341820fb0e0344f29a41945"
-
-[[package]]
-name = "volatile"
-version = "0.4.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e4c2dbd44eb8b53973357e6e207e370f0c1059990df850aca1eca8947cf464f0"
-
-[[package]]
-name = "x86_64"
-version = "0.14.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb611915c917c6296d11e23f71ff1ecfe49c5766daba92cd3df52df6b58285b6"
-dependencies = [
- "bit_field",
- "bitflags",
- "volatile 0.4.4",
-]

Cargo.toml

@@ -2,31 +2,18 @@
 name = "blog_os"
 version = "0.1.0"
 authors = ["Philipp Oppermann <dev@phil-opp.com>"]
-edition = "2018"
-
-[[test]]
-name = "should_panic"
-harness = false
-
-[[test]]
-name = "stack_overflow"
-harness = false
+edition = "2024"
 
 [dependencies]
 bootloader = "0.9"
 volatile = "0.2.6"
 spin = "0.5.2"
-x86_64 = "0.14.2"
-uart_16550 = "0.2.0"
 
 [dependencies.lazy_static]
 version = "1.0"
 features = ["spin_no_std"]
 
-
-[package.metadata.bootimage]
-test-args = [
-    "-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "stdio",
-    "-display", "none"
-]
-test-success-exit-code = 33         # (0x10 << 1) | 1
+[[bin]]
+name = "blog_os"
+test = false
+bench = false

README.md

@@ -1,10 +1,10 @@
-# Blog OS (Double Faults)
+# Blog OS (VGA Text Mode)
 
-[![Build Status](https://github.com/phil-opp/blog_os/workflows/Code/badge.svg?branch=post-06)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Code%22+branch%3Apost-06)
+[![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)
 
-This repository contains the source code for the [Double Faults][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
+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.
 
-[post]: https://os.phil-opp.com/double-fault-exceptions/
+[post]: https://os.phil-opp.com/vga-text-mode/
 
 **Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
 
@@ -56,10 +56,6 @@ 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.
 
-## Testing
-
-To run the unit and integration tests, execute `cargo xtest`.
-
 ## License
 
 Licensed under either of

src/gdt.rs

@@ -1,52 +0,0 @@
-use lazy_static::lazy_static;
-use x86_64::structures::gdt::{Descriptor, GlobalDescriptorTable, SegmentSelector};
-use x86_64::structures::tss::TaskStateSegment;
-use x86_64::VirtAddr;
-
-pub const DOUBLE_FAULT_IST_INDEX: u16 = 0;
-
-lazy_static! {
-    static ref TSS: TaskStateSegment = {
-        let mut tss = TaskStateSegment::new();
-        tss.interrupt_stack_table[DOUBLE_FAULT_IST_INDEX as usize] = {
-            const STACK_SIZE: usize = 4096 * 5;
-            static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE];
-
-            let stack_start = VirtAddr::from_ptr(&raw const STACK);
-            let stack_end = stack_start + STACK_SIZE;
-            stack_end
-        };
-        tss
-    };
-}
-
-lazy_static! {
-    static ref GDT: (GlobalDescriptorTable, Selectors) = {
-        let mut gdt = GlobalDescriptorTable::new();
-        let code_selector = gdt.add_entry(Descriptor::kernel_code_segment());
-        let tss_selector = gdt.add_entry(Descriptor::tss_segment(&TSS));
-        (
-            gdt,
-            Selectors {
-                code_selector,
-                tss_selector,
-            },
-        )
-    };
-}
-
-struct Selectors {
-    code_selector: SegmentSelector,
-    tss_selector: SegmentSelector,
-}
-
-pub fn init() {
-    use x86_64::instructions::segmentation::{Segment, CS};
-    use x86_64::instructions::tables::load_tss;
-
-    GDT.0.load();
-    unsafe {
-        CS::set_reg(GDT.1.code_selector);
-        load_tss(GDT.1.tss_selector);
-    }
-}

src/interrupts.rs

@@ -1,37 +0,0 @@
-use crate::{gdt, println};
-use lazy_static::lazy_static;
-use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
-
-lazy_static! {
-    static ref IDT: InterruptDescriptorTable = {
-        let mut idt = InterruptDescriptorTable::new();
-        idt.breakpoint.set_handler_fn(breakpoint_handler);
-        unsafe {
-            idt.double_fault
-                .set_handler_fn(double_fault_handler)
-                .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX);
-        }
-        idt
-    };
-}
-
-pub fn init_idt() {
-    IDT.load();
-}
-
-extern "x86-interrupt" fn breakpoint_handler(stack_frame: InterruptStackFrame) {
-    println!("EXCEPTION: BREAKPOINT\n{:#?}", stack_frame);
-}
-
-extern "x86-interrupt" fn double_fault_handler(
-    stack_frame: InterruptStackFrame,
-    _error_code: u64,
-) -> ! {
-    panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
-}
-
-#[test_case]
-fn test_breakpoint_exception() {
-    // invoke a breakpoint exception
-    x86_64::instructions::interrupts::int3();
-}

src/lib.rs

@@ -1,78 +0,0 @@
-#![no_std]
-#![cfg_attr(test, no_main)]
-#![feature(custom_test_frameworks)]
-#![feature(abi_x86_interrupt)]
-#![test_runner(crate::test_runner)]
-#![reexport_test_harness_main = "test_main"]
-
-use core::panic::PanicInfo;
-
-pub mod gdt;
-pub mod interrupts;
-pub mod serial;
-pub mod vga_buffer;
-
-pub fn init() {
-    gdt::init();
-    interrupts::init_idt();
-}
-pub trait Testable {
-    fn run(&self) -> ();
-}
-
-impl<T> Testable for T
-where
-    T: Fn(),
-{
-    fn run(&self) {
-        serial_print!("{}...\t", core::any::type_name::<T>());
-        self();
-        serial_println!("[ok]");
-    }
-}
-
-pub fn test_runner(tests: &[&dyn Testable]) {
-    serial_println!("Running {} tests", tests.len());
-    for test in tests {
-        test.run();
-    }
-    exit_qemu(QemuExitCode::Success);
-}
-
-pub fn test_panic_handler(info: &PanicInfo) -> ! {
-    serial_println!("[failed]\n");
-    serial_println!("Error: {}\n", info);
-    exit_qemu(QemuExitCode::Failed);
-    loop {}
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(u32)]
-pub enum QemuExitCode {
-    Success = 0x10,
-    Failed = 0x11,
-}
-
-pub fn exit_qemu(exit_code: QemuExitCode) {
-    use x86_64::instructions::port::Port;
-
-    unsafe {
-        let mut port = Port::new(0xf4);
-        port.write(exit_code as u32);
-    }
-}
-
-/// Entry point for `cargo xtest`
-#[cfg(test)]
-#[no_mangle]
-pub extern "C" fn _start() -> ! {
-    init();
-    test_main();
-    loop {}
-}
-
-#[cfg(test)]
-#[panic_handler]
-fn panic(info: &PanicInfo) -> ! {
-    test_panic_handler(info)
-}

src/main.rs

@@ -1,47 +1,20 @@
 #![no_std]
 #![no_main]
-#![feature(custom_test_frameworks)]
-#![test_runner(blog_os::test_runner)]
-#![reexport_test_harness_main = "test_main"]
 
-use blog_os::println;
 use core::panic::PanicInfo;
 
-#[no_mangle]
+mod vga_buffer;
+
+#[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
     println!("Hello World{}", "!");
 
-    blog_os::init();
-
-    fn stack_overflow() {
-        stack_overflow(); // for each recursion, the return address is pushed
-    }
-
-    // uncomment line below to trigger a stack overflow
-    // stack_overflow();
-
-    #[cfg(test)]
-    test_main();
-
-    println!("It did not crash!");
     loop {}
 }
 
 /// This function is called on panic.
-#[cfg(not(test))]
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     println!("{}", info);
     loop {}
 }
-
-#[cfg(test)]
-#[panic_handler]
-fn panic(info: &PanicInfo) -> ! {
-    blog_os::test_panic_handler(info)
-}
-
-#[test_case]
-fn trivial_assertion() {
-    assert_eq!(1, 1);
-}

src/serial.rs

@@ -1,37 +0,0 @@
-use lazy_static::lazy_static;
-use spin::Mutex;
-use uart_16550::SerialPort;
-
-lazy_static! {
-    pub static ref SERIAL1: Mutex<SerialPort> = {
-        let mut serial_port = unsafe { SerialPort::new(0x3F8) };
-        serial_port.init();
-        Mutex::new(serial_port)
-    };
-}
-
-#[doc(hidden)]
-pub fn _print(args: ::core::fmt::Arguments) {
-    use core::fmt::Write;
-    SERIAL1
-        .lock()
-        .write_fmt(args)
-        .expect("Printing to serial failed");
-}
-
-/// Prints to the host through the serial interface.
-#[macro_export]
-macro_rules! serial_print {
-    ($($arg:tt)*) => {
-        $crate::serial::_print(format_args!($($arg)*));
-    };
-}
-
-/// Prints to the host through the serial interface, appending a newline.
-#[macro_export]
-macro_rules! serial_println {
-    () => ($crate::serial_print!("\n"));
-    ($fmt:expr) => ($crate::serial_print!(concat!($fmt, "\n")));
-    ($fmt:expr, $($arg:tt)*) => ($crate::serial_print!(
-        concat!($fmt, "\n"), $($arg)*));
-}

src/vga_buffer.rs

@@ -169,25 +169,3 @@ pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
     WRITER.lock().write_fmt(args).unwrap();
 }
-
-#[test_case]
-fn test_println_simple() {
-    println!("test_println_simple output");
-}
-
-#[test_case]
-fn test_println_many() {
-    for _ in 0..200 {
-        println!("test_println_many output");
-    }
-}
-
-#[test_case]
-fn test_println_output() {
-    let s = "Some test string that fits on a single line";
-    println!("{}", s);
-    for (i, c) in s.chars().enumerate() {
-        let screen_char = WRITER.lock().buffer.chars[BUFFER_HEIGHT - 2][i].read();
-        assert_eq!(char::from(screen_char.ascii_character), c);
-    }
-}

tests/basic_boot.rs

@@ -1,25 +0,0 @@
-#![no_std]
-#![no_main]
-#![feature(custom_test_frameworks)]
-#![test_runner(blog_os::test_runner)]
-#![reexport_test_harness_main = "test_main"]
-
-use blog_os::println;
-use core::panic::PanicInfo;
-
-#[no_mangle] // don't mangle the name of this function
-pub extern "C" fn _start() -> ! {
-    test_main();
-
-    loop {}
-}
-
-#[panic_handler]
-fn panic(info: &PanicInfo) -> ! {
-    blog_os::test_panic_handler(info)
-}
-
-#[test_case]
-fn test_println() {
-    println!("test_println output");
-}

tests/should_panic.rs

@@ -1,25 +0,0 @@
-#![no_std]
-#![no_main]
-
-use blog_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
-use core::panic::PanicInfo;
-
-#[no_mangle]
-pub extern "C" fn _start() -> ! {
-    should_fail();
-    serial_println!("[test did not panic]");
-    exit_qemu(QemuExitCode::Failed);
-    loop {}
-}
-
-fn should_fail() {
-    serial_print!("should_panic::should_fail...\t");
-    assert_eq!(0, 1);
-}
-
-#[panic_handler]
-fn panic(_info: &PanicInfo) -> ! {
-    serial_println!("[ok]");
-    exit_qemu(QemuExitCode::Success);
-    loop {}
-}

tests/stack_overflow.rs

@@ -1,58 +0,0 @@
-#![no_std]
-#![no_main]
-#![feature(abi_x86_interrupt)]
-
-use blog_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
-use core::panic::PanicInfo;
-use lazy_static::lazy_static;
-use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
-
-#[no_mangle]
-pub extern "C" fn _start() -> ! {
-    serial_print!("stack_overflow::stack_overflow...\t");
-
-    blog_os::gdt::init();
-    init_test_idt();
-
-    // trigger a stack overflow
-    stack_overflow();
-
-    panic!("Execution continued after stack overflow");
-}
-
-#[allow(unconditional_recursion)]
-fn stack_overflow() {
-    stack_overflow(); // for each recursion, the return address is pushed
-    volatile::Volatile::new(0).read(); // prevent tail recursion optimizations
-}
-
-lazy_static! {
-    static ref TEST_IDT: InterruptDescriptorTable = {
-        let mut idt = InterruptDescriptorTable::new();
-        unsafe {
-            idt.double_fault
-                .set_handler_fn(test_double_fault_handler)
-                .set_stack_index(blog_os::gdt::DOUBLE_FAULT_IST_INDEX);
-        }
-
-        idt
-    };
-}
-
-pub fn init_test_idt() {
-    TEST_IDT.load();
-}
-
-extern "x86-interrupt" fn test_double_fault_handler(
-    _stack_frame: InterruptStackFrame,
-    _error_code: u64,
-) -> ! {
-    serial_println!("[ok]");
-    exit_qemu(QemuExitCode::Success);
-    loop {}
-}
-
-#[panic_handler]
-fn panic(info: &PanicInfo) -> ! {
-    blog_os::test_panic_handler(info)
-}

x86_64-blog_os.json

@@ -3,13 +3,14 @@
     "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",
+    "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"
+    "features": "-mmx,-sse,+soft-float",
+    "rustc-abi": "x86-softfloat"
   }