Merge branch 'post-05' into post-06

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

Cargo.lock

@@ -26,8 +26,6 @@ version = "0.1.0"
 dependencies = [
  "bootloader",
  "lazy_static",
- "pc-keyboard",
- "pic8259",
  "spin 0.5.2",
  "uart_16550",
  "volatile 0.2.7",
@@ -36,9 +34,9 @@ dependencies = [
 
 [[package]]
 name = "bootloader"
-version = "0.9.32"
+version = "0.9.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ea119c3ed05625c179e09d17d0914570a3753ca09c890a73d98f6b72aea00d2"
+checksum = "7bdfddac270bbdd45903296bc1caf29a7fdce6b326aaf0bbab7f04c5f98b7447"
 
 [[package]]
 name = "lazy_static"
@@ -49,21 +47,6 @@ dependencies = [
  "spin 0.9.8",
 ]
 
-[[package]]
-name = "pc-keyboard"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed089a1fbffe3337a1a345501c981f1eb1e47e69de5a40e852433e12953c3174"
-
-[[package]]
-name = "pic8259"
-version = "0.10.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb844b5b01db1e0b17938685738f113bfc903846f18932b378bc0eabfa40e194"
-dependencies = [
- "x86_64",
-]
-
 [[package]]
 name = "rustversion"
 version = "1.0.22"

Cargo.toml

@@ -18,8 +18,6 @@ volatile = "0.2.6"
 spin = "0.5.2"
 x86_64 = "0.14.2"
 uart_16550 = "0.2.0"
-pic8259 = "0.10.1"
-pc-keyboard = "0.7.0"
 
 [dependencies.lazy_static]
 version = "1.0"
@@ -27,7 +25,7 @@ features = ["spin_no_std"]
 
 [[bin]]
 name = "blog_os"
-test = false
+test = true
 bench = false
 
 

README.md

@@ -1,10 +1,10 @@
-# Blog OS (Hardware Interrupts)
+# Blog OS (Double Faults)
 
-[![Build Status](https://github.com/phil-opp/blog_os/workflows/Code/badge.svg?branch=post-07)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Code%22+branch%3Apost-07)
+[![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)
 
-This repository contains the source code for the [Hardware Interrupts][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
+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.
 
-[post]: https://os.phil-opp.com/hardware-interrupts/
+[post]: https://os.phil-opp.com/double-fault-exceptions/
 
 **Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
 

src/interrupts.rs

@@ -1,32 +1,7 @@
-use crate::{gdt, print, println};
+use crate::{gdt, println};
 use lazy_static::lazy_static;
-use pic8259::ChainedPics;
-use spin;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
 
-pub const PIC_1_OFFSET: u8 = 32;
-pub const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8;
-
-#[derive(Debug, Clone, Copy)]
-#[repr(u8)]
-pub enum InterruptIndex {
-    Timer = PIC_1_OFFSET,
-    Keyboard,
-}
-
-impl InterruptIndex {
-    fn as_u8(self) -> u8 {
-        self as u8
-    }
-
-    fn as_usize(self) -> usize {
-        usize::from(self.as_u8())
-    }
-}
-
-pub static PICS: spin::Mutex<ChainedPics> =
-    spin::Mutex::new(unsafe { ChainedPics::new(PIC_1_OFFSET, PIC_2_OFFSET) });
-
 lazy_static! {
     static ref IDT: InterruptDescriptorTable = {
         let mut idt = InterruptDescriptorTable::new();
@@ -36,8 +11,6 @@ lazy_static! {
                 .set_handler_fn(double_fault_handler)
                 .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX);
         }
-        idt[InterruptIndex::Timer.as_usize()].set_handler_fn(timer_interrupt_handler);
-        idt[InterruptIndex::Keyboard.as_usize()].set_handler_fn(keyboard_interrupt_handler);
         idt
     };
 }
@@ -57,47 +30,6 @@ extern "x86-interrupt" fn double_fault_handler(
     panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
 }
 
-extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: InterruptStackFrame) {
-    print!(".");
-    unsafe {
-        PICS.lock()
-            .notify_end_of_interrupt(InterruptIndex::Timer.as_u8());
-    }
-}
-
-extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: InterruptStackFrame) {
-    use pc_keyboard::{DecodedKey, HandleControl, Keyboard, ScancodeSet1, layouts};
-    use spin::Mutex;
-    use x86_64::instructions::port::Port;
-
-    lazy_static! {
-        static ref KEYBOARD: Mutex<Keyboard<layouts::Us104Key, ScancodeSet1>> =
-            Mutex::new(Keyboard::new(
-                ScancodeSet1::new(),
-                layouts::Us104Key,
-                HandleControl::Ignore
-            ));
-    }
-
-    let mut keyboard = KEYBOARD.lock();
-    let mut port = Port::new(0x60);
-
-    let scancode: u8 = unsafe { port.read() };
-    if let Ok(Some(key_event)) = keyboard.add_byte(scancode) {
-        if let Some(key) = keyboard.process_keyevent(key_event) {
-            match key {
-                DecodedKey::Unicode(character) => print!("{}", character),
-                DecodedKey::RawKey(key) => print!("{:?}", key),
-            }
-        }
-    }
-
-    unsafe {
-        PICS.lock()
-            .notify_end_of_interrupt(InterruptIndex::Keyboard.as_u8());
-    }
-}
-
 #[test_case]
 fn test_breakpoint_exception() {
     // invoke a breakpoint exception

src/lib.rs

@@ -15,8 +15,6 @@ pub mod vga_buffer;
 pub fn init() {
     gdt::init();
     interrupts::init_idt();
-    unsafe { interrupts::PICS.lock().initialize() };
-    x86_64::instructions::interrupts::enable();
 }
 pub trait Testable {
     fn run(&self) -> ();
@@ -45,7 +43,7 @@ pub fn test_panic_handler(info: &PanicInfo) -> ! {
     serial_println!("[failed]\n");
     serial_println!("Error: {}\n", info);
     exit_qemu(QemuExitCode::Failed);
-    hlt_loop();
+    loop {}
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -64,19 +62,13 @@ pub fn exit_qemu(exit_code: QemuExitCode) {
     }
 }
 
-pub fn hlt_loop() -> ! {
-    loop {
-        x86_64::instructions::hlt();
-    }
-}
-
 /// Entry point for `cargo xtest`
 #[cfg(test)]
 #[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
     init();
     test_main();
-    hlt_loop();
+    loop {}
 }
 
 #[cfg(test)]

src/main.rs

@@ -13,11 +13,18 @@ pub extern "C" fn _start() -> ! {
 
     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!");
-    blog_os::hlt_loop();
+    loop {}
 }
 
 /// This function is called on panic.
@@ -25,7 +32,7 @@ pub extern "C" fn _start() -> ! {
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     println!("{}", info);
-    blog_os::hlt_loop();
+    loop {}
 }
 
 #[cfg(test)]

src/serial.rs

@@ -13,14 +13,10 @@ lazy_static! {
 #[doc(hidden)]
 pub fn _print(args: ::core::fmt::Arguments) {
     use core::fmt::Write;
-    use x86_64::instructions::interrupts;
+    SERIAL1
-
+        .lock()
-    interrupts::without_interrupts(|| {
+        .write_fmt(args)
-        SERIAL1
+        .expect("Printing to serial failed");
-            .lock()
-            .write_fmt(args)
-            .expect("Printing to serial failed");
-    });
 }
 
 /// Prints to the host through the serial interface.

src/vga_buffer.rs

@@ -163,16 +163,11 @@ macro_rules! println {
     ($($arg:tt)*) => ($crate::print!("{}\n", format_args!($($arg)*)));
 }
 
-/// Prints the given formatted string to the VGA text buffer
+/// Prints the given formatted string to the VGA text buffer through the global `WRITER` instance.
-/// through the global `WRITER` instance.
 #[doc(hidden)]
 pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
-    use x86_64::instructions::interrupts;
+    WRITER.lock().write_fmt(args).unwrap();
-
-    interrupts::without_interrupts(|| {
-        WRITER.lock().write_fmt(args).unwrap();
-    });
 }
 
 #[test_case]
@@ -189,16 +184,10 @@ fn test_println_many() {
 
 #[test_case]
 fn test_println_output() {
-    use core::fmt::Write;
-    use x86_64::instructions::interrupts;
-
     let s = "Some test string that fits on a single line";
-    interrupts::without_interrupts(|| {
+    println!("{}", s);
-        let mut writer = WRITER.lock();
+    for (i, c) in s.chars().enumerate() {
-        writeln!(writer, "\n{}", s).expect("writeln failed");
+        let screen_char = WRITER.lock().buffer.chars[BUFFER_HEIGHT - 2][i].read();
-        for (i, c) in s.chars().enumerate() {
+        assert_eq!(char::from(screen_char.ascii_character), c);
-            let screen_char = writer.buffer.chars[BUFFER_HEIGHT - 2][i].read();
+    }
-            assert_eq!(char::from(screen_char.ascii_character), c);
-        }
-    });
 }

x86_64-blog_os.json

@@ -3,7 +3,7 @@
     "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,
     "os": "none",
     "executables": true,