implemented hardware interrupts

added ps2 keyboard support, and added functionality to print pressed
keys to screen

right now the pic8259 keeps sending timer interrupts, but im just
handling them with a function that just prints a period to the vga
buffer. need to implement stuff for multiple threads

Cargo.lock

@@ -29,6 +29,21 @@ 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"
@@ -41,6 +56,8 @@ version = "0.1.0"
 dependencies = [
  "bootloader",
  "lazy_static",
+ "pc-keyboard",
+ "pic8259",
  "spin 0.5.2",
  "uart_16550",
  "volatile 0.2.7",

Cargo.toml

@@ -26,6 +26,8 @@ volatile = "0.2.6"
 spin = "0.5.2"
 x86_64 = "0.14.2"
 uart_16550 = "0.6.0"
+pic8259 = "0.10.1"
+pc-keyboard = "0.7.0"
 
 [dependencies.lazy_static]
 version = "1.0"

src/interrupts.rs

@@ -1,7 +1,15 @@
 use lazy_static::lazy_static;
+use pic8259::ChainedPics;
+use spin;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
 
-use crate::{gdt, println};
+use crate::{gdt, print, println};
+
+pub const PIC_1_OFFSET: u8 = 32;
+pub const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8;
+
+pub static PICS: spin::Mutex<ChainedPics> =
+    spin::Mutex::new(unsafe { ChainedPics::new(PIC_1_OFFSET, PIC_2_OFFSET) });
 
 lazy_static! {
     static ref IDT: InterruptDescriptorTable = {
@@ -12,6 +20,8 @@ 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(kyb_interrupt_handler);
         idt
     };
 }
@@ -29,6 +39,60 @@ extern "x86-interrupt" fn double_fault_handler(
 ) -> ! {
     panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
 }
+extern "x86-interrupt" fn timer_interrupt_handler(_stack_hanfler: InterruptStackFrame) {
+    print!(".");
+    unsafe {
+        PICS.lock()
+            .notify_end_of_interrupt(InterruptIndex::Timer.as_u8());
+    }
+}
+extern "x86-interrupt" fn kyb_interrupt_handler(_stack_frame: InterruptStackFrame) {
+    use pc_keyboard::{DecodedKey, HandleControl, Keyboard, ScancodeSet1, layouts};
+    use spin::Mutex;
+    use x86_64::instructions::port::Port;
+
+    static 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());
+    }
+}
+
+#[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())
+    }
+}
 
 #[test_case]
 fn test_breakpoint_exception() {

src/lib.rs

@@ -15,6 +15,17 @@ pub mod vga_buffer;
 pub fn init() {
     interrupts::init_idt();
     gdt::init();
+    unsafe {
+        interrupts::PICS.lock().initialize();
+    }
+    x86_64::instructions::interrupts::enable();
+}
+
+// cpu halter for efficiency
+pub fn hlt_loop() -> ! {
+    loop {
+        x86_64::instructions::hlt();
+    }
 }
 
 // shit to make functions and methods testable
@@ -47,7 +58,7 @@ pub fn test_panic_handler(info: &PanicInfo) -> ! {
     serial_println!("[failed]\n");
     serial_println!("Error: {}\n", info);
     exit_qemu(QemuExitCode::Failed);
-    loop {}
+    hlt_loop();
 }
 
 // this this is here cuz lib.rs built separately, so need test for lib functions as well
@@ -57,7 +68,7 @@ pub fn test_panic_handler(info: &PanicInfo) -> ! {
 pub extern "C" fn _start() -> ! {
     init();
     test_main();
-    loop {}
+    hlt_loop();
 }
 
 #[cfg(test)]

src/main.rs

@@ -18,7 +18,7 @@ pub extern "C" fn _start() -> ! {
     test_main();
 
     println!("it didnt fucking crash!");
-    loop {}
+    rusty_os::hlt_loop();
 }
 
 // called on panic -> only when run, not in test
@@ -26,7 +26,7 @@ pub extern "C" fn _start() -> ! {
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     println!("{}", info);
-    loop {}
+    rusty_os::hlt_loop();
 }
 
 // panic handler for tests

src/serial.rs

@@ -11,10 +11,14 @@ lazy_static! {
 #[doc(hidden)]
 pub fn _print(args: ::core::fmt::Arguments) {
     use core::fmt::Write;
-    SERIAL1
-        .lock()
-        .write_fmt(args)
-        .expect("Printing to resial failed!");
+    use x86_64::instructions::interrupts;
+
+    interrupts::without_interrupts(|| {
+        SERIAL1
+            .lock()
+            .write_fmt(args)
+            .expect("Printing to resial failed!");
+    });
 }
 
 // macro that prints to host thru serial interface

src/vga_buffer.rs

@@ -147,7 +147,13 @@ macro_rules! println {
 #[doc(hidden)]
 pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
-    WRITER.lock().write_fmt(args).unwrap();
+    use x86_64::instructions::interrupts;
+
+    interrupts::without_interrupts(|| {
+        // prevents deadlock by making sure the main thread is not interrupted by
+        // anything requiring to print shit
+        WRITER.lock().write_fmt(args).unwrap();
+    });
 }
 
 // VGA Buffer tests:
@@ -169,10 +175,17 @@ fn test_println_many() {
 // check printed shits appear on screen
 #[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";
-    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);
-    }
+
+    interrupts::without_interrupts(|| {
+        let mut writer = WRITER.lock();
+        writeln!(writer, "\n{}", s).expect("writeln failed");
+        for (i, c) in s.chars().enumerate() {
+            let screen_char = writer.buffer.chars[BUFFER_HEIGHT - 2][i].read();
+            assert_eq!(char::from(screen_char.ascii_character), c);
+        }
+    });
 }